Petar Mamić

Petar started off by playing in Dinamo's Hitrec-Kacian football academy.{{cite web|title=Petar Mamić|url=https://footballtalentscout.net/2014/02/26/petar-mamic/|work=Football Talent Scout|date=26 February 2014|access-date=4 April 2018}} With Dinamo's pioneers he won three titles from 2008 to 2009 to 2010–11 and with the cadets he won one title in 2012–13.{{cite web|title=Pobjednici u obje kategorije do sada|url=http://prva-hnl.hr/blog/prva-hnl-juniorikadeti/pobjednici-u-obje-kategorije-do-sada-2/|work=Prva HNL|access-date=16 July 2014|language=hr|url-status=dead|archive-url=https://web.archive.org/web/20110213060252/http://prva-hnl.hr/blog/prva-hnl-juniorikadeti/pobjednici-u-obje-kategorije-do-sada-2/|archive-date=13 February 2011}} Besides these titles he won the 2014 Mladen Ramljak Tournament with the cadets scoring a total of five goals,{{cite web|title=Pala i Rijeka; sjajni Modri s četiri pobjede osvojili Ramljak|url=http://www.tportal.hr/sport/nogomet/336375/Mlade-nade-Dinama-na-nikad-jacem-turniru-Mladen-Ramljak.html|work=T Portal|access-date=16 July 2014|language=hr}}{{cite web|title=Turnir Mladen Ramljak 2014.|url=http://gnkdinamo.hr/hr/skola/turnir-mladen-ramljak/mladen-ramljak-2014/pala-i-rijeka;-sjajni-modri-s-cetiri-pobjede-osvojili-ramljak!.html|work=GNK Dinamo Zagreb|access-date=16 July 2014|language=hr}} won the silver medal with the cadets on the 2014 Zayed International Football Cup{{cite web|title=Kadeti srebrni u Abu Dhabiju|url=http://gnkdinamo.hr/hr/skola/vijesti/kadeti-srebrni-u-abu-dhabiju1.html|work=GNK Dinamo Zagreb|access-date= 16 July 2014|language=Croatian}} and, with the juniors, won the 2014 Tournament of Turopolje.{{cite web|title=Juniori Dinama osvojili Trofej Turopolja 2014.|url=http://gnkdinamo.hr/hr/skola/vijesti-skole/juniori-dinama-osvojili-trofej-turopolja-2014.html|work=GNK Dinamo Zagreb|access-date=3 September 2014|language=hr}} He went with Luka Capan on football trials with the seniors and made his debut for the seniors, donning the number 15, in a 3–1 win against NK Istra 1961 on 6 February 2014 playing the first half.{{cite web|title=Istra 1961 vs Dinamo Zagreb|url=https://int.soccerway.com/matches/2014/02/06/croatia/1-hnl/nk-istra-1961-pula/nk-dinamo-zagreb/1480366/|work=Soccerway|access-date=18 February 2014}} However, Mamić and Capan were put on the B squad after the 2014 summer transfer window{{cite web|title=Dinamo II|url=http://gnkdinamo.hr/dinamo2/momcad.html|work=GNK Dinamo Zagreb|access-date= 30 September 2014|language=Croatian}} to serve as backup for the seniors.{{cite web|title=Uspješan tijek priprema mlađih uzrasta Dinama|url=http://gnkdinamo.hr/hr/skola/vijesti-skole/uspjesan-tijek-priprema-mladih-uzrasta-dinama.html|work=GNK Dinamo Zagreb|access-date= 3 September 2014|language=Croatian}}

Mamić debuted for the B team, this time wearing the number 26, in a friendly 4–0 win over NK Hrvatski Dragovoljac on 20 July 2014.{{cite web|title=Dinamo II startao furioznom igrom i visokom pobjedom|url=http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-startao-furioznom-igrom-i-visokom-pobjedom.html|work=GNK Dinamo Zagreb|access-date= 30 September 2014|language=Croatian}} Mamić proceeded to play seven more friendlies{{cite web|title=Miklić s dva gola preokrenuo utakmicu i osigurao pobjedu |url=http://gnkdinamo.hr/dinamo2/vijesti/miklic-s-dva-pogotka-preokrenuo-vodstvo-trnja-i-osigurao-pobjedu-dinamu-ii.html|work=GNK Dinamo Zagreb|access-date= 30 September 2014|language=Croatian}}{{cite web|title=Theophilus pogodio za pobjedu Rijeke II|url=http://gnkdinamo.hr/dinamo2/vijesti/theophilus-pogodio-za-pobjedu-rijeke-ii.html|work=GNK Dinamo Zagreb|access-date=30 September 2014|language=hr}}{{cite web|title=Dinamovih 15 pogodaka, Škvorc četiri puta proparao mrežu|url=http://gnkdinamo.hr/dinamo2/vijesti/dinamovih-15-pogodaka,-skvorc-cetiri-puta-parao-mrezu.html|work=GNK Dinamo Zagreb|access-date=30 September 2014|language=hr}}{{cite web|title=Dinamo II zabio šesticu, debitirao Taravel|url=http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-zabio-sesticu,-debitirao-taravel.html|work=GNK Dinamo Zagreb|access-date=30 September 2014|language=hr}}{{cite web|title=Kad spiker nakon 10. gola kaže: "Bilo bi dosta više, stvarno..."|url=http://gnkdinamo.hr/dinamo2/vijesti/kad-spiker-nakon-dinamova-10.-gola-kaze-%E2%80%9Ebilo-bi-dosta-vise,-stvarno...%E2%80%9C.html|work=GNK Dinamo Zagreb|access-date=30 September 2014|language=hr}} earning a red card in the sixth game{{cite web|title=Podravina slavila, Dinamo II nije mogao s igračem manje|url=http://gnkdinamo.hr/dinamo2/vijesti/podravina-slavila,-dinamo-ii-nije-mogao-s-igracem-manje.html|work=GNK Dinamo Zagreb|access-date=30 September 2014|language=hr}} before suffering a concussion in the seventh game after a strong blow to the head only minutes after having scored his first goal for the B team against {{Interlanguage link multi|NK Jedinstvo Sveti Križ Začretje|hr}}.{{cite web|title=PETICA DINAMA, DOMAĆIMA NISU POMOGLI NI MLINARIĆ NITI BOBEK|url=http://www.gnkdinamo.hr/hr/Novosti/Clanak/%E2%80%9Cpetica%E2%80%9C-dinama-ii,-jedinstvu-nisu-pomogli-ni-mlinaric-niti-bobek|work=GNK Dinamo|access-date=10 February 2018|language=hr}}{{cite web|title=MAMIĆ DO PETKA U BOLNICI, NA TRAVNJAKU ZA DVA DO TRI TJEDNA|url=https://www.gnkdinamo.hr/hr/Novosti/Clanak/mamic-do-petka-u-bolnici,-na-travnjaku-za-dva-do-tri-tjedna|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}} Following his injury, he was replaced by Nicolas Taravel{{cite web|title=Gujić u juniore, Acheampong i Taravel oplemenili momčad|url=http://gnkdinamo.hr/dinamo2/vijesti/gujic-u-juniore,-acheampong-i-taravel-oplemenili-momcad.html|work=GNK Dinamo Zagreb|access-date=30 September 2014|language=hr}} but resumed training after only a week{{cite web|title=Oporavljenici Petar Mamić i Bojan Knežević opet u pogonu|url=http://gnkdinamo.hr/dinamo2/vijesti/oporavljenici-petar-mamic-i-bojan-knezevic-opet-u-pogonu.html|work=GNK Dinamo Zagreb|date=4 September 2014|access-date=30 September 2014|language=hr|archive-url=https://web.archive.org/web/20141006113448/http://gnkdinamo.hr/dinamo2/vijesti/oporavljenici-petar-mamic-i-bojan-knezevic-opet-u-pogonu.html|archive-date=6 October 2014}} making a comeback, and also debut in the league, five days later, on 9 September, in a 5–2 win over NK Moslavina.{{cite web|title=Škvorc potjerao plave do pobjede, povratak Kneževića i Mamića|url=http://gnkdinamo.hr/dinamo2/vijesti/skvorc-potjerao-dinamo-do-pobjede-u-kutini,-povratak-knezevica-i-mamica.html|work=GNK Dinamo Zagreb|date=9 September 2014|access-date=30 September 2014|language=hr|archive-url=https://web.archive.org/web/20141006081252/http://gnkdinamo.hr/dinamo2/vijesti/skvorc-potjerao-dinamo-do-pobjede-u-kutini,-povratak-knezevica-i-mamica.html|archive-date=6 October 2014}} Mamić, after having played one more league game,{{cite web|title="Starom dužniku" zabili šest, Bekić pogodio rašlje za gol sezone|url=http://gnkdinamo.hr/dinamo2/vijesti/uzivo-dinamo-ii-dugo-selo-10.html|work=GNK Dinamo Zagreb|date=27 September 2014|access-date=30 September 2014|language=hr|archive-date=6 October 2014|archive-url=https://web.archive.org/web/20141006105408/http://gnkdinamo.hr/dinamo2/vijesti/uzivo-dinamo-ii-dugo-selo-10.html}} was called in for the U-19 national team to participate in the 2015 UEFA European Under-19 Championship qualification and missed out on three league games before returning, on 14 October, in a friendly against {{Interlanguage link multi|NK Libertas Novska|hr}}.{{cite web|title=Povratak reprezentativaca, dinamovci šesticom kroz Novsku|url=http://gnkdinamo.hr/dinamo2/vijesti/povratak-reprezentativaca,-dinamovci-sesticom-kroz-novsku.html|work=GNK Dinamo Zagreb|access-date=16 October 2014|language=hr}} Mamić returned to the league on 18 October, playing full-time and earning a yellow card in a tie with NK Vrbovec.{{cite web|title=Prvi remi u sezoni, Bekića zaustavila stativa, Badjija greda|url=http://gnkdinamo.hr/dinamo2/vijesti/prvi-remi-u-sezoni,-bekica-zaustavila-stativa,-badjija-greda.html|work=GNK Dinamo Zagreb|date=18 October 2014|access-date=29 November 2014|language=hr|archive-url=https://web.archive.org/web/20141204183803/http://gnkdinamo.hr/dinamo2/vijesti/prvi-remi-u-sezoni,-bekica-zaustavila-stativa,-badjija-greda.html|archive-date=4 December 2014}} Mamić played five more games in the fall season,{{cite web|title=Dinamu II pobjeda protiv sjajnog HAŠK-a, Badji opet srijelac|url=http://gnkdinamo.hr/dinamo2/vijesti/dinamu-ii-pobjeda-protiv-sjajnog-hask-a,-badji-opet-srijelac.html|work=GNK Dinamo Zagreb|date=31 October 2014|access-date=29 November 2014|language=hr|archive-url=https://web.archive.org/web/20141204184046/http://gnkdinamo.hr/dinamo2/vijesti/dinamu-ii-pobjeda-protiv-sjajnog-hask-a,-badji-opet-srijelac.html|archive-date=4 December 2014}}{{cite web|title=Opet prvi: plavi svladali Špansko, Rijeka II 'pala' protiv Stupnika|url=http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-na-vrhu-plavi-svladali-spansko,-rijeka-ii-pala-protiv-stupnika.html|work=GNK Dinamo Zagreb|access-date=29 November 2014|language=hr|date=5 November 2014|archive-url=https://web.archive.org/web/20141204184201/http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-na-vrhu-plavi-svladali-spansko,-rijeka-ii-pala-protiv-stupnika.html|archive-date=4 December 2014}}{{cite web|title=Dinamo II jesenski prvak, Riječanima bod u Trnju|url=http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-jesenski-prvak,-rijecanima-bod-u-trnju.html|work=GNK Dinamo Zagreb|access-date=29 November 2014|language=hr}} earning two more yellow cards{{cite web|title=Dinamo II opet u starom ritmu: Maksimiru zabili osam pogodaka|url=http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-opet-u-starom-ritmu-maksimiru-zabili-osam-pogodaka.html|work=GNK Dinamo Zagreb|date=8 November 2014|access-date=29 November 2014|language=hr|archive-url=https://web.archive.org/web/20141204184049/http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-opet-u-starom-ritmu-maksimiru-zabili-osam-pogodaka.html|archive-date=4 December 2014}} and scoring his first ever league goal from a penalty, on 29 November, in a 3–1 win over NK Rijeka II.{{cite web|title=Dinamo II visokom pobjedom u Rijeci zaključio sjajnu polusezonu|url=http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-visokom-pobjedom-u-rijeci-zakljucio-sjajnu-polusezonu.html|work=GNK Dinamo Zagreb|date=29 November 2014|access-date=29 November 2014|language=hr|archive-url=https://web.archive.org/web/20141204183503/http://gnkdinamo.hr/dinamo2/vijesti/dinamo-ii-visokom-pobjedom-u-rijeci-zakljucio-sjajnu-polusezonu.html|archive-date=4 December 2014}}

Mamić was speculated to be kept in the B team so as to maintain Dinamo B's domination in the league in hopes of moving up to Druga HNL, especially after Mario Musa was called back to Dinamo's seniors.{{cite web|title=ZAMJENA ZA IBANEZA Mamić odustao od 'kapitalca' na lijevom boku, vraća se Musa iz Lokomotive|url=https://www.jutarnji.hr/zamjena-za-ibaneza-mamic-odustao-od--kapitalca--na-lijevom-boku--vraca-se-musa-iz-lokosa/1262238/|work=Jutarnji list|access-date=10 February 2018|language=hr}} However, on 8 January 2015, Lokomotiva announced that Mamić had been loaned out to them for the rest of the season, along with Franko Andrijašević and Dino Perić.{{cite web|title=Franko Andrijašević, Petar Mamić i Dino Perić novi su igrači Lokomotive!|url=http://nklokomotiva.hr/vijesti.php?id_vijesti=5446|work=NK Lokomotiva|access-date=10 January 2015|language=Croatian}}{{cite web|title=Andrijašević, Mamić i Perić iz Dinama u Lokomotivu|url=http://www.goal.com/hr/news/6997/prva-hnl/2015/01/08/7775192/andrija%C5%A1evi%C4%87-mami%C4%87-i-peri%C4%87-iz-dinama-u-lokomotivu|work=Goal.com|access-date=10 February 2018|language=hr}}{{cite web|title=Nova pojačanja u NK Lokomotiva!|url=https://www.scena.hr/sport/pojacanja-u-nk-lokomotiva/|work=Scena.hr|access-date=10 February 2018|language=hr}}{{cite web|title=Franko Andrijašević sam tražio posudbu u Lokomotivu|url=https://www.vecernji.hr/sport/franko-andrijasevic-sam-trazio-posudbu-u-lokomotivu-983166|work=Večernji list|access-date=10 February 2018|language=hr}}

Mamić debuted for NK Lokomotiva on 18 January 2015, wearing the number 3, in a friendly 3–0 win over NK Vrapče.{{cite web|title=Lokomotiva - Vrapče 3:0|url=http://nklokomotiva.hr/vijesti.php?id_vijesti=5449|work=NK Lokomotiva|access-date=20 January 2015|language=hr|archive-url=https://web.archive.org/web/20150120115134/http://nklokomotiva.hr/vijesti.php?id_vijesti=5449|archive-date=20 January 2015}} Mamić went to Rovinj on trials with the team and played all of the matches of the {{Interlanguage link multi|Arena Kup|hr|3=Arena Cup (nogomet)}}.{{cite web|title=Arena Cup, Medulin 2015: Lokomotiva - Slaven Belupo 2:2|url=http://www.nklokomotiva.hr/vijesti.php?id_vijesti=5452|work=NK Lokomotiva|date=21 January 2015|access-date=7 February 2015|language=hr|archive-url=https://web.archive.org/web/20150207235601/http://www.nklokomotiva.hr/vijesti.php?id_vijesti=5452|archive-date=7 February 2015}}{{cite web|title=Lokomotiva - OFK Beograd 2:1|url=http://www.nklokomotiva.hr/vijesti.php?id_vijesti=5453|work=NK Lokomotiva|date=23 January 2014|access-date=7 February 2015|language=hr|archive-url=https://web.archive.org/web/20150207234826/http://www.nklokomotiva.hr/vijesti.php?id_vijesti=5453|archive-date=7 February 2015}}{{cite web|title=Finale Arena Kupa: Lokomotiva - Istra 0:2|url=http://www.nklokomotiva.hr/vijesti.php?id_vijesti=5454|work=NK Lokomotiva|date=25 January 2015|access-date=7 February 2015|language=hr|archive-url=https://web.archive.org/web/20150207230622/http://www.nklokomotiva.hr/vijesti.php?id_vijesti=5454|archive-date=7 February 2015}} Mamić debuted for the team in the league on 7 February in a 1–2 loss against GNK Dinamo Zagreb.{{cite web|title=Dinamo golovima Ademija i Henriqueza bez većih problema savladao solidnu Lokomotivu|author=Ante Dubravac|date=7 February 2015|url=http://www.hrsport.net/vijesti/482028/nogomet-maxtv-prva-liga/dinamo-golovima-ademija-i-henriqueza-bez-vecih-problema-savladao-solidnu-lokomotivu/|work=Sportnet|access-date=10 February 2018|language=hr}} Three weeks later he was a last-minute substitute{{cite web|title=Video: Kolar pogotkom u 88. minuti ostavio Istru 1961 na samo tri pobjede|author=Josip Piršljin|date=27 February 2015|url=http://www.hrsport.net/vijesti/482828/nogomet-maxtv-prva-liga/video-kolar-pogotkom-u-88-minuti-ostavio-istru-1961-na-samo-tri-pobjede/|work=Sportnet|access-date=10 February 2018|language=hr}} and was substituted in on two more games{{cite web|title=Vugrinec u razmaku od minute dva puta zatresao mrežu i potopio Lokomotivu|url=http://www.hrsport.net/vijesti/483413/nogomet-maxtv-prva-liga/vugrinec-u-razmaku-od-minute-dva-puta-zatresao-mrezu-i-potopio-lokomotivu/|work=Sportnet|access-date=10 February 2018|language=hr}}{{cite web|title=Video: Tri penala, autogol, hat-trick Krstanovića i katastrofa Lokomotive u Kranjčevićevoj|author=Branimir Korać|url=http://www.hrsport.net/vijesti/484098/nogomet-maxtv-prva-liga/video-tri-penala-autogol-hat-trick-krstanovica-i-katastrofa-lokomotive-u-kranjcevicevoj/|work=Sportnet|date=3 April 2015|access-date=13 November 2015|language=Croatian}} before being given another chance to play in the starting roster again in a 1–2 loss against Dinamo.{{cite web|title=Sluga nije mogao sve obraniti: Soudani opet zabija, Henriquez dodao jedan, Lokosi tek ublažili poraz|url=http://www.hrsport.net/vijesti/484601/nogomet-maxtv-prva-liga/sluga-nije-mogao-sve-obraniti-soudani-opet-zabija-henriquez-dodao-jedan-lokosi-tek-ublazili-poraz/|work=Sportnet|author=Borna Rupnik|date=17 April 2015|access-date=10 February 2018|language=hr}} Mamić was once more a substitute{{cite web|title=Video: Istra 1961 se izvukla iz zaostatka i uzela važne bodove u borbi za ostanak|url=http://www.hrsport.net/vijesti/485274/nogomet-maxtv-prva-liga/video-istra-1961-se-izvukla-iz-zaostatka-i-uzela-vazne-bodove-u-borbi-za-ostanak/|work=Sportnet|access-date=10 February 2018|language=hr}} and finally got to play three full games in a row at the end of the season, even earning two yellow cards.{{cite web|title=Lokomotiva pregažena na Kantridi, sve riješeno već u prvom poluvremenu|url=http://www.hrsport.net/vijesti/485514/nogomet-maxtv-prva-liga/lokomotiva-pregazena-na-kantridi-sve-rijeseno-vec-u-prvom-poluvremenu/|work=Sportnet|access-date= 13 November 2015|language=Croatian}}{{cite web|title=Andrijašević srušio Slaven Belupo i osigurao važna tri boda Lokomotivi|url=http://www.hrsport.net/vijesti/485703/nogomet-maxtv-prva-liga/andrijasevic-srusio-slaven-belupo-i-osigurao-vazna-tri-boda-lokomotivi/|work=Sportnet|access-date=10 February 2018|language=hr}}{{cite web|title=Splitovci po prvi puta do gostujućeg slavlja protiv Lokomotive, Erceg i Rog za uvjerljivih 3:0|url=http://www.hrsport.net/vijesti/486065/nogomet-maxtv-prva-liga/splitovci-po-prvi-puta-do-gostujuceg-slavlja-protiv-lokomotive-erceg-i-rog-za-uvjerljivih-30/|work=Sportnet|access-date= 13 November 2015|language=Croatian}} Mamić also played both quarter-final games against NK Rijeka in the 2014–15 Croatian Football Cup and earned a yellow card in the first game.{{cite web|title=Rijeka visokom pobjedom u prvom susretu napravila veliki korak prema polufinalu Kupa|url=http://www.hrsport.net/vijesti/482194/nogomet-kup/rijeka-visokom-pobjedom-u-prvom-susretu-napravila-veliki-korak-prema-polufinalu-kupa/|author=Branimir Korać|work=Sportnet|date=11 February 2015|access-date=10 February 2018|language=hr}}{{cite web|title=Rijeka ništa nije prepustila slučaju: s nova četiri gola izbacila Lokomotivu|url=http://www.hrsport.net/vijesti/483027/nogomet-kup/rijeka-nista-nije-prepustila-slucaju-s-nova-cetiri-gola-izbacila-lokomotivu/|work=Sportnet|date=4 March 2015|access-date=10 February 2018}}

Lokomotiva had qualified for the 2015–16 UEFA Europa League so Mamić went with the team on trials in Slovenia{{cite web|title=Pripremne utakmice: Inter, Astra Giurgiu i Ružomberoka|url=http://www.nklokomotiva.hr/vijest/pripremne-utakmice-inter-astra-giurgiu-i-ruzomberoka-4|work=NK Lokomotiva|access-date=10 February 2018|language=hr}} and debuted in the Europa League on 9 July 2015 in the second leg of the First round in a 2–2 draw against Welsh side Airbus UK Broughton F.C.{{cite web|title=EUROPA LEAGUE / 1st qualifying round 2nd leg|url=http://airbusfc.com/index.php/match|work=Airbus UK Broughton FC|access-date=10 February 2018|language=hr}}{{cite web|title=Lokomotiva - Airbus 2:2|url=http://www.nklokomotiva.hr/vijest/lokomotiva-airbus-2-2-9|work=NK Lokomotiva|access-date=10 February 2018|language=hr}} He remained on the bench in the Second round against P.A.O.K. with Lokomotiva eventually being expelled with a 3–7 aggregate score.{{cite web|title=Lokomotiva - PAOK 2:1|url=http://nklokomotiva.hr/vijest/lokomotiva-paok-2-1-11|work=NK Lokomotiva|access-date=29 February 2016|language=Croatian}}{{cite web|title=Uzvrat drugog pretkola: PAOK - Lokomotiva|url=http://nklokomotiva.hr/vijest/uzvrat-drugog-pretkola-paok-lokomotiva-15|work=NK Lokomotiva|access-date=10 February 2018|language=hr}} Mamić was benched for the first three games of the 2015-16 season before being transferred back to Dinamo Zagreb 2{{cite web|title=1. kolo: Split - Lokomotiva 2:1|url=http://nklokomotiva.hr/vijest/1.-kolo-split-lokomotiva-2-1-7|work=NK Lokomotiva|access-date=10 February 2018|language=hr}}{{cite web|title=Lokomotiva - Istra 6:1|url=http://nklokomotiva.hr/vijest/lokomotiva-istra-6-1-14|work=NK Lokomotiva|access-date=10 February 2018|language=hr}}{{cite web|title=3. kolo: Slaven Belupo - Lokomotiva 2:2|url=http://nklokomotiva.hr/vijest/3.-kolo-slaven-belupo-lokomotiva-2-2-19|work=NK Lokomotiva|access-date=10 February 2018|language=hr}} to enable Dinamo to loan out Borna Barišić to Lokomotiva seeing as they had already loaned out six players to them.{{refn|Six was the maximum number of players that could be loaned out from one club to another in the same league level as per the decision of the 2015 HNS Assembly, article 52, paragraph 2.{{cite web|title=Skupština Hrvatskon nogometnog saveza|url=http://hns-cff.hr/files/documents/122/Pravilnik%20o%20statusu%20igraca%20i%20registraciji%202016%20procisceni%20tekst.pdf|work=HNS|access-date=10 February 2018|language=hr}}|group="note"|name="Skupština HNS"}}{{cite web|title=Mamićeva sprdoludnja s propisima HNS-a: ovoga ljeta u Lokomotivu stiglo 14 igrača|url=http://www.slobodnadalmacija.hr/sport/domaci-nogomet/clanak/id/286033/mamiceva-sprdoludnja-s-propisima-hns-a-ovoga-ljeta-u-lokomotivu-stiglo-14-igraca|work=Slobodna Dalmacija|date=11 September 2015|access-date=10 February 2018|language=hr}}

Having left NK Lokomotiva, Mamić returned in the second round of the 2015–16 Croatian Second Football League on 22 August 2015 in a 2–0 loss against HNK Šibenik.{{cite web|title=2.HNL: Šibenik pobijedio Dinamo II, a Dugopolje Segestu|url=http://dalmatinskiportal.hr/sport/2-hnl--sibenik-pobijedio-dinamo-ii--a-dugopolje-segestu/6741|work=dalmatinskiportal.hr|access-date=10 February 2018|language=hr}} He played four more games{{cite web|title=Dinamo 2 remizirao sa Cibalijom; zaigrao Sigali, nova ozljeda Pavičića|url=http://www.goal.com/hr/news/6935/sve-vijesti/2015/10/31/16863282/dinamo-2-remizirao-sa-cibalijom-zaigrao-sigali-nova-ozljeda|work=goal.com|access-date=10 February 2018|language=hr}}{{cite web|title=Dinamo Zagreb II vs. Dugopolje|url=http://www.goal.com/ba/match/dinamo-zagreb-ii-vs-dugopolje/2075029|work=goal.com|access-date=10 February 2018|language=hr}}{{cite web|title=POBJEDA VRATILA SAMOPOUZDANJE Dinamo II - Gorica 1:3 (0:1)|url=http://www.hnk-gorica.hr/hnk2013/sadrzaj/izvjestaji/seniori/dinamo-ii-gorica--1:3-(0:1)|work=HNK Gorica|access-date=10 February 2018|language=hr}}{{cite web|title=8.kolo 2. HNL: Dinamo II – Lučko 2:1 (video)|url=http://sportnedjeljom.hr/8-kolo-2-hnl-dinamo-ii-lucko-21-video/|work=sportnedjeljom.hr|access-date=10 February 2018|language=hr}} before scoring an own goal in a 0–2 loss against NK Rudeš{{cite web|title=DINAMOVCI ZABILI DVAPUT, RUDEŠ SLAVIO SA 2-0|url=http://gnkdinamo.hr/hr/Novosti/Clanak/dinamovci-zabili-dvaput-rudes-slavio-sa-2-0|work=GNK Dinamo|access-date=10 February 2018|language=hr}} as well as earning a yellow card in the next match.{{cite web|title=FILIPOVIĆ ZABIO ZA POBJEDU SESVETA|url=http://gnkdinamo.hr/hr/Novosti/Clanak/filipovic-zabio-za-pobjedu-sesveta|work=GNK Dinamo|access-date=10 February 2018|language=hr}} He did, however, make up for it after another game{{cite web|title=BEZ POGODAKA U SIGETU, ZAIGRAO DOMAGOJ PAVIČIĆ|url=http://gnkdinamo.hr/hr/Novosti/Clanak/bez-pogodaka-u-sigetu-zaigrao-domagoj-pavicic|work=GNK Dinamo|access-date=10 February 2018|language=hr}} by scoring his first goal of the season, as well as the equalizer, after having received a yellow card, in a 2–1 turnover victory over HNK Šibenik.{{cite web|title=Dinamo 2 preokretom svladao vodeći Šibenik, golčina Mamića!|url=http://www.goal.com/hr/news/6935/sve-vijesti/2015/10/18/16441612/dinamo-2-preokretom-svladao-vode%C4%87i-%C5%A1ibenik-gol%C4%8Dina-mami%C4%87a|work=Goal.com|access-date=10 February 2018|language=hr}} He played two further games,{{cite web|title=GOSTI POVELI, DOMAĆI IZJEDNAČILI|url=http://gnkdinamo.hr/hr/Novosti/Clanak/gosti-poveli-domaci-izjednacili|work=GNK Dinamo|access-date=10 February 2018|language=hr}} receiving a yellow card in the second one{{cite web|title=SIGALI ZAIGRAO, PAVIČIĆ PONOVNO OZLIJEĐEN, DINAMO II REMIZIRAO|url=http://gnkdinamo.hr/hr/Novosti/Clanak/sigali-zaigrao-pavicic-ponovno-ozlijeden-dinamo-ii-remizirao|work=GNK Dinamo|access-date=10 February 2018|language=hr}} before playing a game for the first team in the second round of the 2015-16 Croatian Football Cup against NK Mladost Ždralovi in which he also received a yellow card.{{cite web|title=Mladost Ždralovi - Dinamo Zagreb|url=http://gnkdinamo.hr/hr/Utakmice/2015-2016-mladost-zdralovi-dinamo-zagreb#tab_TeamComposition|work=GNK Dinamo|access-date=10 February 2018|language=hr}} He then missed out on the next match due to accumulated yellow cards and returned on 13 November against HNK Gorica but remained on the bench.{{cite web|title=I vrh HNS-a popratio današnju pobjedu HNK Gorice|url=http://www.vgdanas.hr/Sport/Clanak/13794/i-vrh-hns-a-popratio-danasnju-pobjedu-hnk-gorice.aspx|work=VG Danas|access-date=10 February 2018|language=hr}} Mamić finished the first half of the season playing full-time in both remaining games and earning one more yellow card.{{cite web|title=Dinamo 2 svladao Imotski|url=http://www.goal.com/hr/news/6935/sve-vijesti/2015/11/21/17553892/dinamo-2-svladao-imotski|work=Goal.com|access-date=10 February 2018|language=hr}}{{cite web|title=Dinamo 2 remizirao u Lučkom|url=http://www.goal.com/hr/news/6935/sve-vijesti/2015/11/28/17804332/dinamo-2-remizirao-u-lu%C4%8Dkom?ICID=HP_TS_4|work=Goal.com|access-date=10 February 2018|language=hr}} He played seven warm up games before the start of the second half of the season,{{cite web|title=NK Dinamo Zagreb vs NK Lučko|url=https://www.betbrain.com/football/world/friendly-club-matches/nk-dinamo-zagreb-v-nk-lucko/#!/previous-results|work=Betbrain.com|access-date=10 February 2018}}{{cite web|title=Gorica - Dinamo Z.(B) 2:0|url=http://www.cityportal.hr/gorica-dinamo-z-b-2-0/|work=cityportal.hr|access-date=10 February 2018|language=hr}}{{cite web|title=NK Špansko vs GNK Dinamo Zagreb II Betting|url=https://www.cloudbet.com/en/sports/event/85840|work=cloudbet.com|access-date=10 February 2018}}{{cite web|title=Utakmica protic GNK Dinamo II|url=http://nk-kustosija.hr/utakmica-protiv-gnk-dinamo-ii/|work=NK Kustošija|access-date= 29 February 2016}} including warm ups in Umag.{{cite web|title=GNK Dinamo Zagreb II 1 - 1 NK Rudar Velenje|url=http://nkrudarvelenje.com/sportyresults/gnk-dinamo-zagreb-ii-1-1-nk-rudar-velenje/|work=NK Rudar Velenje|access-date=10 February 2018|language=Slovenian}}{{cite web|title=Pripremna utakmica: Orijent 1919 dobro u Žuknici parirao drugoj momčadi Dinama|url=http://www.sportcom.hr/lokalni-sport/nogomet/cetvrta-liga-z/pipremna-utakmica-orijent-1919-dobro-u-zuknici-parirao-drugoj-momcadi-dinama.html|work=SportCom.hr|access-date= 29 February 2016|language=Croatian}} Mamić continued the season in style scoring the first goal from a penalty in a 3–2 turnover victory against HNK Segesta and giving an assist to Karlo Majić for the equalizer.{{cite web|title=Dinamo II protiv Segeste od 0-2 do 3-2|url=http://www.gnkdinamo.hr/HR/Novosti/Clanak/dinamo-ii-protiv-segeste-od-0-2-do-3-2|work=GNK Dinamo|access-date=10 February 2018|language=hr}} He scored the last goal in a 3–0 victory over NK Rudeš in the very next game from an assist from Bojan Knežević{{cite web|title=Rudeš bez kapetana protiv svog bivšeg trenera|url=http://www.dvoznak.com/?show=dogadjaj&id_dogadjaj=936843&id_vrsta_dogadjaja=1&id_sport=0&id_natjecanje=3756&datum=2016-03-06|work=dovznak.com|access-date=10 February 2018|language=hr}} as well as the last goal in a 2–0 victory two games later against HNK Segesta after an assist by Tibor Halilović.{{cite web|title=Nova pobjeda plavih, Halilović zabio pa asistirao|url=http://gnkdinamo.hr/HR/Novosti/Clanak/nova-pobjeda-plavih-halilovic-zabio-pa-asistirao|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}} Mamić played the next four matches{{cite web|title=Zadrani izborili bod pet minuta prije kraja|url=http://gnkdinamo.hr/HR/Novosti/Clanak/zadrani-izborili-bod-pet-minuta-prije-kraja|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}}{{cite web|title=Bivši dinamovac Havojić odnio bodove iz Maksimira|url=http://gnkdinamo.hr/HR/Novosti/Clanak/bivsi-dinamovac-havojic-odnio-bodove-iz-maksimira|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}}{{cite web|title=Gojak asistirao, Badji zabio za pobjedu u Dugopolju|url=http://gnkdinamo.hr/HR/Novosti/Clanak/gojak-asistirao-badji-zabio-za-pobjedu-u-dugopolju|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}}{{cite web|title=Plavi izdržali s igračem manje i osvojili bod|url=http://gnkdinamo.hr/HR/Novosti/Clanak/plavi-izdrzali-s-igracem-manje-i-osvojili-bod|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}} before playing an excellent match, giving both assists in a 2–1 victory over NK Sesvete and earning a yellow card.{{cite web|title=Mamić i Sosa pripremali, Gogić i Knežević zabili|url=http://gnkdinamo.hr/HR/Novosti/Clanak/mamic-i-sosa-pripremali-gogic-i-knezevic-zabili|work=GNK Dinamo Zagreb|access-date= 24 June 2016|language=Croatian}} He played another two games{{cite web|title=Spretni Vinkovčani svladali oslabljeni Dinamo II|url=http://gnkdinamo.hr/HR/Novosti/Clanak/spretni-vinkovcani-svladali-oslabljeni-dinamo-ii|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}}{{cite web|title=Dinamo II prikočio Šibenčane|url=http://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-ii-prikocio-sibencane|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}} but was forced to miss out on the following match against HNK Gorica after having accumulated two yellow cards.{{cite web|title=Plavi u Veliku Goricu po "revanš"|url=http://gnkdinamo.hr/HR/Novosti/Clanak/plavi-u-veliku-goricu-po-revans|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}} He finished the season playing both remaining games.{{cite web|title=Štrok dragovoljcima otvorio put do pobjede|url=http://gnkdinamo.hr/HR/Novosti/Clanak/strok-dragovoljcima-otvorio-put-do-pobjede|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}}{{cite web|title=Imoćani pobijedili i ostali u Drugoj HNL|url=http://gnkdinamo.hr/HR/Novosti/Clanak/imocani-pobijedili-i-ostali-u-drugoj-hnl|work=GNK Dinamo Zagreb|access-date=10 February 2018|language=hr}}

After the season ended Mamić played in all of the B team's five preseason warm-up games{{cite web|title=Al Nassr bolji od Dinama II u prijateljskoj utakmici|url=https://sportarena.hr/2016/07/24/al-nassr-bolji-od-dinama-ii-u-prijateljskoj-utakmici/|work=sportarena.hr|access-date= 3 September 2016|language=Croatian}}{{cite web|title=Dinamo II zabio šest pogodaka u dvije utakmice|url=http://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-ii-zabio-sest-pogodaka-u-dvije-utakmice|work=GNK Dinamo Zagreb|access-date= 3 September 2016|language=Croatian}}{{cite web|title=Gorica - Dinamo 2:2 (0:1)|url=http://www.hnk-gorica.hr/hnk2013/sadrzaj/izvjestaji/seniori/gorica-dinamo--2:2-(0:1)|work=HNK Gorica|access-date= 3 September 2016|language=Croatian}}{{cite web|title=Maksimir dobrom igrom pobijedio drugoligaša Dinamo II|url=http://www.nk-maksimir.hr/vijesti/2016-08-13.htm|work=NK Maksimir|access-date= 3 September 2016|language=Croatian}} and started the following season playing the second half of the first game against NK Solin and earning a yellow card.{{cite web|title=Dinamo II remizirao na otvaranju sezone|url=http://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-ii-remizirao-na-otvaranju-sezone|work=GNK Dinamo Zagreb|access-date= 3 September 2016|language=Croatian}} He was then benched for the following two games in light of transfer negotiations with Cagliari Calcio{{cite web|title=Cagliari, ultime ore di mercato: vicinissimo Mati Fernandez, stretta per Emanuelson e Keita|url=http://www.unionesarda.it/articolo/sport/2016/08/31/cagliari_ultime_ore_di_mercato_stretta_per_mati_fernandez_e_urby-4-529200.html|work=L'Unione Sarda|access-date= 3 September 2016|language=Italian}} but returned in the following match against NK Novigrad after the 2016 summer transfer window had closed.{{cite web|title=Dani Olmo prekinuo 535 dana dugi niz Novigrađana|url=http://istrasport.eu/web/vijest.asp?id=21626|work=istrasport.eu|access-date= 9 September 2016|language=Croatian}} He went on to play the next three league matches, earning a further two yellow cards{{cite web|title=Dvostruki preokret i pobjeda Dinama: Dinamo II – Rudeš 3:2|url=http://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-ii--rudes-32|work=GNK Dinamo Zagreb|access-date= 26 September 2016|language=Croatian}}{{cite web|title=Plavi svladali vodeću momčad lige: Dinamo II – Dugopolje 1:0|url=http://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-ii--dugopolje-10|work=GNK Dinamo Zagreb|access-date= 26 September 2016|language=Croatian}} but then missed the next game{{cite web|title=Mladi dinamovci već razmišljaju o dolasku Juventusa u juniorskoj LP|url=http://dvoznak.com/?show=dogadjaj&id_dogadjaj=1048719&id_vrsta_dogadjaja=1&id_sport=0&id_natjecanje=4455&datum=2016-09-25|work=dvoznak.com|access-date= 26 September 2016|language=Croatian}} after having been added to the first team's final roster for the 2016-17 UEFA Champions League.{{cite web|title=Dinamo prijavio Kobija Morrisa za Ligu prvaka!|url=http://www.goal.com/hr/news/6950/liga-prvaka/2016/09/26/27897622/dinamo-prijavio-kobija-morrisa-za-ligu-prvaka|work=goal.com|access-date= 26 September 2016|language=Croatian}} Ultimately he was not chosen for the game squad and so returned in the next league match{{cite web|title=Sesvećani izvukli bod s bijele točke|url=http://gnkdinamo.hr/hr/Novosti/Clanak/sesvecani-izvukli-bod-s-bijele-tocke|work=GNK Dinamo Zagreb|access-date= 24 October 2016|language=Croatian}} but was again benched in the next game when, due to many player's absences, six first team players came on.{{cite web|title=Gorica i četvrti put svladala Dinamo II|url=http://gnkdinamo.hr/hr/Novosti/Clanak/gorica-i-cetvrti-put-svladala-dinamo-ii|work=GNK Dinamo Zagreb|access-date= 24 October 2016|language=Croatian}} He played the next game{{cite web|title=Zagreb ulovio bod u Maksimiru|url=http://gnkdinamo.hr/hr/Novosti/Clanak/zagreb-ulovio-bod-u-maksimiru|work=GNK Dinamo Zagreb|access-date= 24 October 2016|language=Croatian}} and then earned a yellow card and scored a last-minute goal in a 3–1 victory over NK Solin with Dinamo one player down.{{cite web|title=Dinamo II i Solin atraktivnim golovima "grijali" gledatelje|url=http://gnkdinamo.hr/hr/Novosti/Clanak/dinamo-ii-i-solin-atraktivnim-golovima-grijali-gledatelje|work=GNK Dinamo Zagreb|access-date= 24 October 2016|language=Croatian}} In the following game he accumulated a second yellow card{{cite web|title=Štrok efektnim golom spasio bod Dragovoljcima|url=https://gnkdinamo.hr/HR/Novosti/Clanak/strok-efektnim-golom-spasio-bod-dragovoljcima|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} causing him to miss the next game but returned immediately after{{cite web|title=Božić osigurao bod Chapeau za Moru|url=https://gnkdinamo.hr/HR/Novosti/Clanak/bozic-osigurao-bod-chapeau-za-moru|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} and then gave an assist to Davor Lovren to put Dinamo ahead in a 1–2 loss against NK Lučko.{{cite web|title=Jedan pogodak i Muharov "sombrero" premalo za bod(ove)|url=https://gnkdinamo.hr/HR/Novosti/Clanak/jedan-pogodak-i-muharov-sombrero-premalo-za-bodove|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} He played the next game, receiving another yellow card,{{cite web|title=Čakarun odnio bodove iz Maksimira|url=https://gnkdinamo.hr/HR/Novosti/Clanak/cakarun-odnio-bodove-iz-maksimira|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} and missed the one after that a week before playing Dinamo's first game of the 2016–17 Premier League International Cup against Swansea City.{{cite web|title=Dinamo U-23 remizirao u Walesu|url=https://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-u-23-remizirao-u-walesu|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} He played the closing game of the half season{{cite web|title=Spektakl na zatvaranju polusezone|url=https://gnkdinamo.hr/HR/Novosti/Clanak/spektakl-na-zatvaranju-polusezone|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} and then the second match of the Premier League International Cup against Chelsea{{cite web|title=Dinamo II slavodobitno protiv Chelseaja|url=https://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-ii-slavodobitno-protiv-chelseaja|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} but was replaced by Kruno Ivančić in the last group match against Feyenoord.{{cite web|title=Dinamo deklasirao Feyenoord za prolazak u četvrtfinale|url=https://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-deklasirao-feyenoord-za-prolazak-u-cetvrtfinale|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} In mid January he started trials before the second half of the season{{cite web|title=Dinamo II startao s pripremama|url=https://gnkdinamo.hr/HR/Novosti/Clanak/dinamo-ii-startao-s-pripremama|work=GNK Dinamo Zagreb|access-date= 26 August 2017|language=Croatian}} but his transfer to Frosinone Calcio was announced before the end of the month.{{cite web|title="U DINAMU NISAM PROŠAO ZATO ŠTO SAM MAMIĆ" Do prije godinu dana bio je predodređen za veliku karijeru, a onda je završio u drugoj talijanskoj ligi|url=http://sportske.jutarnji.hr/nogomet/u-dinamu-nisam-prosao-zato-sto-sam-mamic-do-prije-godinu-dana-bio-je-predodreden-za-veliku-karijeru-a-onda-je-zavrsio-u-drugoj-talijanskoj-ligi/5550767/|work=Sportske Novosti|access-date= 26 August 2017|language=Croatian}}

Mamić was being eyed by a few Italian clubs (including Cagliari) before finally transferring to Frosinone Calcio, which had been relegated to Serie B in the previous season and was hoping to return to Serie A.{{cite web|title="U DINAMU NISAM PROŠAO ZATO ŠTO SAM MAMIĆ" Do prije godinu dana bio je predodređen za veliku karijeru, a onda je završio u drugoj talijanskoj ligi|url=http://sportske.jutarnji.hr/nogomet/u-dinamu-nisam-prosao-zato-sto-sam-mamic-do-prije-godinu-dana-bio-je-predodreden-za-veliku-karijeru-a-onda-je-zavrsio-u-drugoj-talijanskoj-ligi/5550767/|work=Sportske Novosti|access-date= 26 August 2017|language=Croatian}} Having been transferred before the start of the second half of the season{{cite web|title=PETAR MAMIC È UN NUOVO CALCIATORE DEL FROSINONE|url=https://www.frosinonecalcio.com/it/petar-mamic-e-un-nuovo-calciatore-del-frosinone/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}} he was given a trial period to prove himself on the field. After a lackluster performance in the trials his position in the team was uncertain{{cite web|title=FOCUS - Mamic e Besea ancora non sono pronti! Prova deludente dei due ragazzi con la Primavera|url=http://www.tuttofrosinone.com/news/focus-mamic-e-besea-ancora-non-sono-pronti-prova-deludente-dei-due-ragazzi-con-la-primavera-21854|work=tuttofrosinone.com|access-date= 26 August 2017|language=Italian}} but he then joined the youth team as a non-quota player for one game of the Campionato Nazionale Primavera against A.S. Roma.{{cite web|title=PRIMAVERA, FROSINONE – ROMA|url=https://www.frosinonecalcio.com/it/primavera-frosinone-roma/|access-date= 11 September 2017|language=Italian}} After that he was put on the first team for the thirtieth match day. However, he was benched for his first four games,{{cite web|title=BARI - FROSINONE|url=https://www.frosinonecalcio.com/it/bari-frosinone-2/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}}{{cite web|title=FROSINONE - VICENZA|url=https://www.frosinonecalcio.com/it/frosinone-vicenza-2/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}}{{cite web|title=CESENA – FROSINONE, IL TABELLINO|url=https://www.frosinonecalcio.com/it/20480-2/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}}{{cite web|title=SPAL - FROSINONE|url=https://www.frosinonecalcio.com/it/spal-frosinone/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}} missing out on a few training sessions between the second and third games due to a friendly with the Croatia U-21 team{{cite web|title=ALLENAMENTO 21 MARZO|url=https://www.frosinonecalcio.com/it/allenamento-21-marzo/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}}{{cite web|title=ALLENAMENTO 22 MARZO|url=https://www.frosinonecalcio.com/it/allenamento-22-marzo/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}}{{cite web|title=ALLENAMENTO 23 MARZO|url=https://www.frosinonecalcio.com/it/allenamento-23-marzo-2/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}} but managed to return to training immediately after to continue being benched.{{cite web|title=ALLENAMENTO 24 MARZO|url=https://www.frosinonecalcio.com/it/allenamento-24-marzo-2/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}} He then missed the next game only to be benched for two more games.{{cite web|title=TERNANA - FROSINONE|url=https://www.frosinonecalcio.com/it/ternana-frosinone-2/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}}{{cite web|title=FROSINONE - NOVARA|url=https://www.frosinonecalcio.com/it/frosinone-novara/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}} After yet another absence, this time of four games, he returned to the bench for two more games {{cite web|title=FROSINONE - PRO VERCELLI|url=https://www.frosinonecalcio.com/it/frosinone-pro-vercelli-2/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}}{{cite web|title=CARPI - FROSINONE|url=https://www.frosinonecalcio.com/it/carpi-frosinone-4/|work=Frosinone Calcio|access-date= 26 August 2017|language=Italian}} and then missed out on the last game of the season. His final appearance on the bench was for the first leg of the semi-final of the promotional play-offs.{{cite web|title=Carpi-Frosinone 0-0, al 'Cabassi' finisce in pareggio|url=http://www.ilrestodelcarlino.it/modena/carpi-calcio/carpi-frosinone-risultato-1.3151163|work=Il Resto del Carlino|access-date= 11 September 2017|language=Italian}} Having played zero minutes on the field and only nine games on the bench, Mamić had left no discernible mark on the team{{cite web|title=LA STAGIONE DI… Petar Mamic – Voto e commento|url=http://www.tuttofrosinone.com/news/la-stagione-di-petar-mamic-voto-e-commento-23807|work=tuttofrosinone.com|access-date= 26 August 2017|language=Italian}} and was rumored to be loaned out to allow him to play more regularly.{{cite web|title=Il Frosinone pensa anche alle uscite, Mamic va in prestito|url=http://www.atuttapagina.it/2017/07/il-frosinone-pensa-anche-alle-uscite-mamic-va-in-prestito/|work=A tutta pagina|access-date= 27 August 2017|language=Italian}} However, with his trial period finished and Frosinone remaining in Serie B, his departure was completed by the end of July.{{cite web|title=Ascoli Picchio, settimana di lavoro al "Del Duca". Finito periodo di prova per Guzzo e Mamic|url=http://www.picenotime.it/articoli/25323.html|work=Picenotime|access-date= 26 August 2017|language=Italian}}{{cite web|title=Mamić za Goal: Benevento me udaljio iz Serie A, a povratak u HNL nije korak unatrag|url=http://www.goal.com/hr/vijesti/petar-mamic-inter-zapresic/1cxg21u7s7r0n1t590prqe0vgf|work=goal.com|access-date= 30 May 2018|language=Croatian}}

A little over two weeks after leaving Frosinone, it was announced that Mamić was joining NK Inter Zaprešić to strengthen its defense,{{cite web|title=Toplaku ispunjena želja: Inter jači za bivšeg dinamovca|url=https://sportarena.hr/nogomet/hrvatska/toplaku-ispunjena-zelja-inter-jaci-za-bivseg-dinamovca/|work=sportarena.hr|access-date=26 August 2017|language=Croatian}} along with Mato Grgić, after Jakov Filipović had left.{{cite web|title=FILIPOVIĆ OTIŠAO U LOKEREN, MAMIĆ I GRGIĆ DOŠLI|url=http://inter.hr/aktualno/odlazak_jakova_filipovica|work=NK Inter Zaprešić|access-date=26 August 2017|language=Croatian}} His first game for Inter was a friendly 0–5 loss against SK Sturm Graz.{{cite web|title=PRIMILI PET OD STURMA|url=http://www.inter.hr/aktualno/sturm_5_0|work=NK Inter Zaprešić|access-date=11 September 2017|language=Croatian}} Mamić, again donning the number 3, made his competitive debut for Inter and return to the Croatian First Football League on 10 September 2017, earning a yellow card, in a 0–3 loss against his former club NK Lokomotiva.{{cite web|title=LOKOMOTIVA - INTER 3:0|url=http://www.inter.hr/aktualno/lokomotiva-inter-3-0|work=NK Inter Zaprešić|access-date=11 September 2017|language=Croatian}} He played four further league games,{{cite web|title=INTER - DINAMO 1:3|url=http://www.inter.hr/aktualno/inter-dinamo-1-3|work=NK Inter Zaprešić|access-date=22 November 2017|language=Croatian}}{{cite web|title=SPLIT: HAJDUK - INTER Z. 2:0|url=http://hajduk.hr/vijest/hajduk-inter-2-0/9339|work=HNK Hajduk Split|access-date=22 November 2017|language=Croatian}} giving an assist for the equalizer to Tomislav Šarić and earning a yellow card in the second game against HNK Cibalia{{cite web|title=CIBALIA - INTER 1:2|url=http://www.inter.hr/aktualno/inter-cibalia-1-2|work=NK Inter Zaprešić|access-date=22 November 2017|language=Croatian}} as well as earning another yellow in the fourth game against NK Slaven Belupo{{cite web|title=S. BELUPO – INTER 1:2|url=http://www.inter.hr/aktualno/inter-slaven-1-2|work=NK Inter Zaprešić|access-date=22 November 2017|language=Croatian}} and then missed out on one game. He also played two Cup games{{cite web|title=NEDELIŠĆE - INTER 0:6|url=http://www.inter.hr/aktualno/nedelisce-inter-kup-1-16|work=NK Inter Zaprešić|access-date=22 November 2017|language=Croatian}}{{cite web|title=INTER - SESVETE 2:1|url=http://www.inter.hr/aktualno/inter-sesvete-2-1|work=NK Inter Zaprešić|access-date=22 November 2017|language=Croatian}} before scoring his first league goal for the team in a 1–1 draw against NK Istra 1961.{{cite web|title=ISTRA 1961 – INTER 1:1|url=http://www.inter.hr/aktualno/istrainter11|work=NK Inter Zaprešić|access-date=22 November 2017|language=Croatian}} He played the next four league games,{{cite web|title=VELIČANSTVENA INTEROVA POBJEDA!|url=http://www.inter.hr/aktualno/interovapobjeda31|work=NK Inter Zaprešić|access-date=22 November 2017|language=Croatian}} receiving yellow cards in the latter three,{{cite web|title=U RIJECI OSVOJEN VELIK BOD|url=http://www.inter.hr/aktualno/u-rijeci-osvojen-bod|work=NK Inter Zaprešić|access-date=22 November 2017|language=Croatian}}{{cite web|title=INTER – LOKOMOTIVA 1:1|url=http://www.inter.hr/aktualno/inter-lokomotiva-remi-1-1#.Wh0ft7YWfbQ.facebook|work=NK Inter Zaprešić|access-date=28 November 2017|language=Croatian}}{{cite web|title=DINAMO – INTER 1:0|url=http://www.inter.hr/aktualno/dinamo-inter-031217|work=NK Inter Zaprešić|access-date=5 December 2017|language=Croatian}} forcing him to miss the following match. He finished the year playing the last game of the half season{{cite web|title=RAPSODIJA BIJELIH ZA KRAJ POLUSEZONE: HAJDUK - INTER-ZAPREŠIĆ 5:0|url=http://hajduk.hr/vijest/rapsodija-bijelih-za-kraj-polusezone-hajduk--inter-zapresic-5-0/9638|work=HNK Hajduk Split|access-date=30 January 2018|language=Croatian}} and the Cup quarter-final.{{cite web|title=INTER – RIJEKA 1:2|url=http://www.inter.hr/aktualno/inter-rijeka-kup-1-4|work=NK Inter Zaprešić|access-date=30 January 2018|language=Croatian}}

Mamić joined the team in warm-ups before the beginning of the second half of the season {{cite web|title=SENIORSKA MOMČAD ZAPOČINJE S PRIPREMAMA U PONEDJELJAK|url=http://www.inter.hr/aktualno/seniori-pripreme-zapocinju-u-ponedjeljak-inter|work=NK Inter Zaprešić|access-date=30 January 2018|language=Croatian}}{{cite web|title=PRVI TJEDAN ZAKLJUČEN TRENING-UTAKMICOM|url=http://www.inter.hr/aktualno/prvi-tjedan-zakljucen-inter|work=NK Inter Zaprešić|access-date=30 January 2018|language=Croatian}} and then went with the team to Medulin, returning to the {{Interlanguage link multi|Arena Kup|hr|3=Arena Cup (nogomet)}} after three years.{{cite web|title=PRVA MOMČAD U MEDULINU|url=http://www.inter.hr/aktualno/prva-momcad-u-medulinu|work=NK Inter Zaprešić|access-date=30 January 2018|language=Croatian}} He played all three group matches,{{cite web|title=REMI S BELUPOM NA STARTU ARENA KUPA 2018|url=http://www.inter.hr/aktualno/arena_cup_2018_inter_slaven|work=NK Inter Zaprešić|access-date=30 January 2018|language=Croatian}}{{cite web|title=ČETIRI POGOTKA H. DRAGOVOLJCU|url=http://www.inter.hr/aktualno/inter-dragovoljac-medulin|work=NK Inter Zaprešić|access-date=30 January 2018|language=Croatian}} doubling the team's lead in the last game with a header in a 2–0 victory over FK Borac Banja Luka and cementing their spot in the final.{{cite web|title=POBJEDOM NAD BORCEM U FINALE!|url=http://www.inter.hr/aktualno/vijesti-borac-2-0|work=NK Inter Zaprešić|access-date=30 January 2018|language=Croatian}} He went on to play the final, with Inter securing the cup in a 1–0 victory over NK Lokomotiva.{{cite web|title=INTER OSVOJIO ARENA CUP!|url=http://www.inter.hr/aktualno/pobjednik-medulin2018|work=NK Inter Zaprešić|access-date=31 January 2018|language=Croatian}} He finished the warm-ups with the team in one last friendly{{cite web|title=PET GOLOVA U MREŽI SESVETA|url=http://www.inter.hr/aktualno/pet-golova-u-mrezi-sesveta|work=NK Inter Zaprešić|access-date=17 March 2018|language=Croatian}} and then started the latter half of the season playing in the first two games, earning a yellow card in the first one.{{cite web|title=REMI S BELUPOM|url=http://www.inter.hr/aktualno/remi-s-belupom-090218|work=NK Inter Zaprešić|access-date=17 March 2018|language=Croatian}}{{cite web|title=LOŠE PROTIV RUDEŠA|url=http://www.inter.hr/aktualno/lose-protiv-rudesa|work=NK Inter Zaprešić|access-date=17 March 2018|language=Croatian}} He was benched for the third game{{cite web|title=PORAZ OD RIJEKA|url=http://www.inter.hr/aktualno/poraz-od-rijeke|work=NK Inter Zaprešić|access-date=17 March 2018|language=Croatian}} but returned to the starting roster in the very next game{{cite web|title=OSIJEK – INTER 1:1|url=http://www.inter.hr/aktualno/osijek-inter-remi|work=NK Inter Zaprešić|access-date=17 March 2018|language=Croatian}} and then scored a goal in the following game against NK Lokomotiva which was misjudged offside only to give an own goal assist to Lokomotiva's Toni Datković, thus securing Inter a 2–3 turnover victory.{{cite web|title=BRILJANTNA POBJEDA NAD LOKOMOTIVOM|url=http://www.inter.hr/aktualno/pobjeda-nad-lokomotivom|work=NK Inter Zaprešić|access-date=17 March 2018|language=Croatian}} He missed out on the following game because of the 2019 UEFA European Under-21 Championship qualification and returned for the following two games{{cite web|title=VRIJEDAN REMI S DINAMOM|url=http://www.inter.hr/aktualno/inter-dinamo-310318|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}}{{cite web|title=POKVARILI TOPLAKOV JUBILEJ|url=http://www.inter.hr/aktualno/pokvarili-niz|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}} but was then again absent for a game. He joined the team for a friendly charity game against NK Međimurec{{cite web|title=ČETIRI POGOTKA U MEĐIMURJU|url=http://www.inter.hr/aktualno/medjimurecnk|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}} and returned as a substitute in the next league game.{{cite web|title=MINUS TRI PRETVORILI U VELIK BOD!|url=http://www.inter.hr/aktualno/minus-tri-pretvorili-u-tri|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}} Mamić played the remaining six games of the season in the starting roster,{{cite web|title=KOLOSALNA POBJEDA U PULI|url=http://www.inter.hr/aktualno/istra-inter-270418|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}}{{cite web|title=INTER – OSIJEK 1:0|url=http://www.inter.hr/aktualno/inter-rudes-vijesti230418|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}}{{cite web|title=RIJEKA – INTER 5:1|url=http://www.inter.hr/aktualno/rijeka-inter080518|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}}{{cite web|title=INTER – LOKOMOTIVA 1:2|url=http://www.inter.hr/aktualno/inter-lokomotiva-1-2|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}}{{cite web|title=DINAMO – INTER 3:1|url=http://www.inter.hr/aktualno/dinamo-inter-190518|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}} earning a yellow in the first of these,{{cite web|title=INTER – RUDEŠ 1:1|url=http://www.inter.hr/aktualno/inter-rudes-vijesti230418|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}} as well as playing two more friendlies.{{cite web|title=SENIORI SVLADALI JUNIORE 2:1|url=http://www.inter.hr/aktualno/seniori-juniori-010518|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}}{{cite web|title=NOVA VES - INTER-ZAPREŠIĆ|url=http://www.inter.hr/aktualno/vijestinovaves|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}} With the season coming to an end, rumors started circulating that Mamić, who still contractually had one more season with Inter,{{cite web|title=PETAR MAMIĆ UOČI DINAMA|url=http://www.inter.hr/aktualno/vijestimamic180518|work=NK Inter Zaprešić|access-date=30 May 2018|language=Croatian}} was being eyed by a few other Croatian clubs, namely Dinamo and Rijeka.{{cite web|title=NA MAKSIMIRU SE SVE GLASNIJE SPOMINJE POVRATAK DINAMOVOG DJETETA KOJE JE SREĆU POTRAŽILO U ITALIJI Mladi Mamić se okolnim putem vraća u Dinamo!?|url=https://sportske.jutarnji.hr/nogomet/transferi/na-maksimiru-se-sve-glasnije-spominje-povratak-dinamovog-djeteta-koje-je-srecu-potrazilo-u-italiji-mladi-mamic-se-okolnim-putem-vraca-u-dinamo/7321962/|work=Sportske novosti|date=5 May 2018|access-date=30 May 2018|language=Croatian}}

On 15 June HNK Rijeka officially announced that Mamić had been transferred to the team{{cite web|title=Petar Mamić novi igrač Rijeke: 'Moja iskrena želja je dvostruka kruna'|url=http://www.nk-rijeka.hr/vijest/petar-mamic-novi-igrac-rijeke-moja-iskrena-zelja-je-dvostruka-kruna/|work=HNK Rijeka|access-date=22 June 2018|language=Croatian}} and three days later during his introduction confirmed it to be on a four-year contract to compete with Leonard Zhuta for the starting left back position.{{cite web|title=Petar Mamić: Rijeka je najbolji izbor za mene|url=http://www.nk-rijeka.hr/vijest/petar-mamic-rijeka-je-najbolji-izbor-za-mene/|work=HNK Rijeka|access-date=22 June 2018|language=Croatian}} He debuted for the team wearing the number 19 on 22 June in a friendly against Balzan F.C.{{cite web|title=Rijeka pobijedila Balzan u prvoj pripremnoj utakmici|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-balzan-u-prvoj-pripremnoj-utakmici/|work=HNK Rijeka|access-date=25 June 2018|language=Croatian}} and scored his first (and second) goal for the team in the very next friendly on 27 June against {{Interlanguage link multi|NK Kraljevica|hr|3=NK Kraljevica}}.{{cite web|title=Rijeka pobijedila Kraljevicu na nogometnoj fešti u Oštrom|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-kraljevicu-na-nogometnoj-festi-u-ostrom/|work=HNK Rijeka|access-date=27 June 2018|language=Croatian}} He played in the following six friendlies{{cite web|title=Rijeka protiv Vukovara upisala treću pobjedu u pripremnom periodu|url=http://www.nk-rijeka.hr/vijest/rijeka-protiv-vukovara-upisala-trecu-pobjedu-u-pripremnom-periodu/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}}{{cite web|title=Kranjska Gora: Rijeka uvjerljivo nadigrala Žilinu|url=http://www.nk-rijeka.hr/vijest/kranjska-gora-rijeka-uvjerljivo-nadigrala-zilinu/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}}{{cite web|title=Rijeka pobijedila Luton, prekrasan pogodak Gorgona|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-luton-prekrasan-pogodak-gorgona/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}} giving assists in three of them.{{cite web|title=Rijeka sjajnom igrom nadigrala Spartak, Čolak dvostruki strijelac|url=http://www.nk-rijeka.hr/vijest/rijeka-sjajnom-igrom-nadigrala-spartak-colak-dvostruki-strijelac/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}}{{cite web|title=Rijeka pobijedila Tabor u jednoj od posljednjih provjera pred novu sezonu|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-tabor-u-jednoj-od-posljednjih-provjera-pred-novu-sezonu/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}}{{cite web|title=Rijeka golijadom protiv Zadra najavila početak prvenstva|url=http://www.nk-rijeka.hr/vijest/rijeka-golijadom-protiv-zadra-najavila-pocetak-prvenstva/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}} As the season started, Mamić had to wait for the second game to debut on the bench wearing the number 3, after two more absences in the league (as well as the Europa League) played another friendly{{cite web|title=Rijeka pobijedila Brinje iz Grosuplja u trening utakmici|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-brinje-iz-grosuplja-u-trening-utakmici/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}} and then after a final league absence debuted as a last-minute substitute on 2 September in a 1–1 draw against GNK Dinamo{{cite web|title=Dinamo – Rijeka 1:1, Raspopović sjajnim golom donio remi|url=http://www.nk-rijeka.hr/vijest/dinamo-rijeka-11-raspopovic-sjajnim-golom-donio-remi/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}} before missing out the next friendly due to obligations with the national under-21 team.{{cite web|title=Petar Mamić dobio predpoziv u reprezentaciju Hrvatske (U-21)|url=http://www.nk-rijeka.hr/vijest/petar-mamic-dobio-predpoziv-u-reprezentaciju-hrvatske-u-21/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}}{{cite web|title=Petru Mamiću poziv u reprezentaciju Hrvatske (U-21)|url=http://www.nk-rijeka.hr/vijest/petru-mamicu-poziv-u-reprezentaciju-hrvatske-u-21/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}} Upon returning he immediately played his first full game in the starting roster on 16 September in a 1–1 draw against NK Osijek as Zhuta was injured{{cite web|title=Rijeka – Osijek 1:1|url=http://www.nk-rijeka.hr/vijest/rijeka-osijek-11-2/|work=HNK Rijeka|access-date=26 September 2018|language=Croatian}} but was then benched for the next league game with his position taken up by right-back Mario Pavelić.{{cite web|title=Lokomotiva – Rijeka 2:0|url=http://www.nk-rijeka.hr/vijest/lokomotiva-rijeka-20-2/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} With Zhuta back in form, he was benched in the first round of the Cup{{cite web|title=Radnik – Rijeka: pogledajte sažetak utakmice i izjavu Denisa Bušnje|url=http://www.nk-rijeka.hr/vijest/radnik-rijeka-pogledajte-sazetak-utakmice-i-izjavu-denisa-busnje/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} and completely off the team for the next six matches, only playing the second round of the Cup{{cite web|title=Kup Hrvatske: Rijeka pobijedila Varaždin, Čolak donio slavlje u nadoknadi!|url=http://www.nk-rijeka.hr/vijest/kup-hrvatske-rijeka-pobijedila-varazdin-colak-donio-slavlje-u-nadoknadi/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} and being called up for two fixtures with the national under-21 side again.{{cite web|title=Darko Velkovski i Petar Mamić pozvani u reprezentaciju|url=http://www.nk-rijeka.hr/vijest/darko-velkovski-i-petar-mamic-pozvani-u-reprezentaciju/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} He came back to the bench and on against Dinamo on 24 November as a right-back substitute after Momčilo Raspopović had been injured.{{cite web|title=Rijeka – Dinamo 1:0, Čolak srušio modre!|url=http://www.nk-rijeka.hr/vijest/rijeka-dinamo-10-colak-srusio-modre/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} He finally returned to his natural position and the starting roster in the next game as Zhuta had accumulated yellows, playing the full match, earning a yellow{{cite web|title=Osijek – Rijeka 1:2, Čolak donio bodove u Gradskom vrtu|url=http://www.nk-rijeka.hr/vijest/osijek-rijeka-12-colak-donio-bodove-u-gradskom-vrtu/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} and finished the first half of the season on the bench on both the Cup quarter-final and last league match.{{cite web|title=Lokomotiva – Rijeka 1:2 (sažetak)|url=http://www.nk-rijeka.hr/vijest/lokomotiva-rijeka-12-sazetak/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}}{{cite web|title=Rijeka – Lokomotiva 3:0 (sažetak)|url=http://www.nk-rijeka.hr/vijest/rijeka-lokomotiva-30-sazetak/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}}

As Leonard Zhuta had been transferred to Konyaspor in the winter transfer window, a new first squad left-back option had to be decided upon. Petar went to Albufeira with the team on warm-ups before the second half of the season and played in all three friendlies,{{cite web|title=Rijeka poražena od Wolfsburga u prvoj pripremnoj utakmici|url=http://www.nk-rijeka.hr/vijest/rijeka-porazena-od-wolfsburga-u-prvoj-pripremnoj-utakmicirijeka-porazena-od-wolfsburga-u-prvoj-pripremoj-utakmici/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}}{{cite web|title=Rijeka pobijedila Servette u drugoj provjeri u Portugalu|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-servette-u-drugoj-provjeri-u-portugalu/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}}{{cite web|title=Rijeka svladala Beijing, Bušnja lijepim pogotkom donio pobjedu|url=http://www.nk-rijeka.hr/vijest/rijeka-svladala-beijing-busnja-lijepim-pogotkom-donio-pobjedu/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} as well as the last friendly, played on home-ground.{{cite web|title=Rijeka pobijedila Krško u posljednjoj provjeri pred nastavak prvenstva|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-krsko-u-posljednjoj-provjeri-pred-nastavak-prvenstva-2/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} As the second half of the season started, Mamić became a standard member of the starting roster playing full-time in the first seven games,{{cite web|title=Rijeka – Hajduk 0:0|url=http://www.nk-rijeka.hr/vijest/rijeka-hajduk-00-4/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}}{{cite web|title=Rijeka preokrenula protiv Rudeša, Gorgon i Puljić potvrdili pobjedu|url=http://www.nk-rijeka.hr/vijest/rijeka-preokrenula-protiv-rudesa-gorgon-i-puljic-potvrdili-pobjedu/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}}{{cite web|title=Rijeka – Istra 1961 2:0, Gorgon i Murić matirali žuto-zelene|url=http://www.nk-rijeka.hr/vijest/rijeka-istra-1961-20-gorgon-i-muric-matirali-zuto-zelene/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} beginning with a 1–1 draw against NK Slaven Belupo in which he even had a chance at goal.{{cite web|title=Slaven Belupo – Rijeka 1:1, bijeli prokockali pobjedu|url=http://www.nk-rijeka.hr/vijest/slaven-belupo-rijeka-11-bijeli-prokockali-pobjedu/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} In this set of games, he gave two assists, one to Maxwell Acosty against HNK Gorica on 2 February{{cite web|title=Rijeka – Gorica 1:3|url=http://www.nk-rijeka.hr/vijest/rijeka-gorica-13/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} and one to Jakov Puljić against GNK Dinamo on 10 March,{{cite web|title=Dinamo – Rijeka 3:1|url=http://www.nk-rijeka.hr/vijest/dinamo-rijeka-31-2/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} both for the leading goal in games that would eventually end in 1–3 losses. He also received a yellow card in the latter game and second overall after having received one four games prior.{{cite web|title=Inter – Rijeka 0:3, bijeli u deset minuta do pobjede|url=http://www.nk-rijeka.hr/vijest/inter-rijeka-03-bijeli-u-deset-minuta-do-pobjede/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} As he had been called up for the national under-21 side once again, he missed out on the next league match as well as a friendly.{{cite web|title=Robert Murić i Petar Mamić pozvani u reprezentaciju Hrvatske (U-21)|url=http://www.nk-rijeka.hr/vijest/robert-muric-i-petar-mamic-pozvani-u-reprezentaciju-hrvatske-u-21/|work=HNK Rijeka|access-date=24 March 2019|language=Croatian}} Upon returning he played three games{{cite web|title=Lokomotiva – Rijeka 1:2, Gorgon i Puljić donijeli pobjedu|url=http://www.nk-rijeka.hr/vijest/lokomotiva-rijeka-12-gorgon-i-puljic-donijeli-pobjedu/|work=HNK Rijeka|access-date=21 April 2019|language=Croatian}}{{cite web|title=Rijeka – Slaven 2:0, Murić i Puljić za novo slavlje bijelih|url=http://www.nk-rijeka.hr/vijest/rijeka-slaven-20-muric-i-puljic-za-novo-slavlje-bijelih/|work=HNK Rijeka|access-date=21 April 2019|language=Croatian}}{{cite web|title=Gorica – Rijeka 1:0|url=http://www.nk-rijeka.hr/vijest/gorica-rijeka-10/|work=HNK Rijeka|access-date=21 April 2019|language=Croatian}} but then missed out on the following two due to a suspected strain.{{cite web|title=VIDEO: IGOR BIŠĆAN SVJESTAN JE ONOGA ŠTO GA ČEKA U JADRANSKOM DERBIJU NA POLJUDU 'Ako budemo igrali kao zadnji put nećemo imati šanse protiv Hajduka'|url=https://sportske.jutarnji.hr/nogomet/hnl/video-igor-biscan-svjestan-je-onoga-sto-ga-ceka-u-jadranskom-derbiju-na-poljudu-ako-budemo-igrali-kao-zadnji-put-necemo-imati-sanse-protiv-hajduka/8761454/|work=Sportske novosti|access-date=21 April 2019|language=Croatian}} Mamić returned to for the Cup semi-final{{cite web|title=Rijeka pobijedila Inter i izborila finale Kupa Hrvatske!|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-inter-i-izborila-finale-kupa-hrvatske/|work=HNK Rijeka|access-date=30 June 2019|language=Croatian}} and next league game in which he earned a yellow card.{{cite web|title=Rijeka – Rudeš 3:1|url=http://www.nk-rijeka.hr/vijest/rijeka-rudes-31/|work=HNK Rijeka|access-date=30 June 2019|language=Croatian}} After a benching, Petar played full-time in the next two matches,{{cite web|title=Rijeka – Dinamo 0:0|url=http://www.nk-rijeka.hr/vijest/rijeka-dinamo-00-3/|work=HNK Rijeka|access-date=30 June 2019|language=Croatian}} earning a yellow and giving an assist to Antonio Čolak for the leading goal in the second one on 15 May, an eventual 1–2 loss against NK Osijek.{{cite web|title=Osijek – Rijeka 2:1|url=http://www.nk-rijeka.hr/vijest/osijek-rijeka-21-2/|work=HNK Rijeka|access-date=30 June 2019|language=Croatian}} He only played the last nine minutes of the following game due to a progression of osteomyelitis of the pubis and because of this finished the season on the bench in both the last league game, as well as the Cup final.{{cite web|title=Rijeka pobijedila Lokomotivu i potvrdila drugo mjesto|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-lokomotivu-i-potvrdila-drugo-mjesto/|work=HNK Rijeka|access-date=30 June 2019|language=Croatian}}{{cite web|title=LIJEVI BEK RIJEKE U ZADNJI TREN OTKAZAO POZIV IZBORNIKA GRAČANA 'Nije pošteno ići na Euro a da nisam na sto posto i pritom da uzmem nekome mjesto'|url=https://sportske.jutarnji.hr/nogomet/reprezentacija/lijevi-bek-rijeke-u-zadnji-tren-otkazao-poziv-izbornika-gracana-nije-posteno-ici-na-euro-a-da-nisam-na-sto-posto-i-pritom-da-uzmem-nekome-mjesto/8967422/|work=Sportske novosti|date=5 June 2019|access-date=30 June 2019|language=Croatian}}

Still recovering from the osteomyelitis which had plagued him for the last nine rounds of the previous season, and in view of HNK Rijeka rejecting a proposition to acquire Giorgos Valerianos{{cite web|title=Bišćan čeka lijevoga beka, Rijeci su ponuđene usluge Grka Valerianosa...|url=http://www.novilist.hr/Sport/NK-Rijeka/Biscan-ceka-lijevoga-beka-Rijeci-su-ponudene-usluge-Grka-Valerianosa|work=Novi list|access-date=30 June 2019|language=Croatian}} while at the same time eyeing Abdu Conté,{{cite web|title=Troyes preotima Rijeci Abdua Contea, lijevog beka iz Sporting B?|url=http://novilist.hr/Sport/NK-Rijeka/Troyes-preotima-Rijeci-Abdua-Contea-lijevog-beka-iz-Sporting-B|work=Novi list|access-date=30 June 2019|language=Croatian}} both left backs, Mamić joined the team on trials on 17 June{{cite web|title=Pogledajte fotogaleriju prvog dana priprema nogometaša Rijeke|url=http://www.nk-rijeka.hr/vijest/pogledajte-fotogaleriju-prvog-dana-priprema-nogometasa-rijeke/|work=HNK Rijeka|access-date=30 June 2019|language=Croatian}} and started them in style by scoring the opening goal in a friendly 3–1 victory over NK Bravo on 21 June.{{cite web|title=Rijeka pobijedila Bravo u prvoj pripremnoj utakmici|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-bravo-u-prvoj-pripremnoj-utakmici/|work=HNK Rijeka|access-date=30 June 2019|language=Croatian}} However, seeing as he had not adequately recovered, Mamić was unable to join the team on the rest of the trials in Rijeka and Kranjska Gora and then missed out on the Croatian Super Cup and all four of Rijeka's games in the UEFA Europa League third qualifying round and Play-off round as well as the first five rounds of the League. He finally returned to the bench for the next round on 1 September against NK Inter and on to the pitch in the next game, a friendly against HNK Šibenik on 7 September.{{cite web|title=Rijeka – Šibenik 1:0, Andrijašević povratak obilježio golom|url=http://www.nk-rijeka.hr/vijest/rijeka-sibenik-10-andrijasevic-povratak-obiljezio-golom/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} Mamić continued being benched for the following five rounds before yet another absence, but appeared in the Cup, playing full-time in both the Second round on 1 October against {{Interlanguage link multi|NK Buje|hr}}, scoring the seventh goal in an 11–0 victory,{{cite web|title=Rijeka pobijedila Buje, prvijenci Vuka, Smolčića i Mamića|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-buje-prvijenci-vuka-smolcica-i-mamica/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} as well as the Round of sixteen on 30 October against NK Varaždin, scoring the opener in a minimal 2–1 victory.{{cite web|title=Rijeka pobijedila Varaždin i izborila četvrtfinale Kupa Hrvatske|url=http://www.nk-rijeka.hr/vijest/rijeka-pobijedila-varazdin-i-izborila-cetvrtfinale-kupa-hrvatske/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} Between these cup games, Mamić played two friendlies{{cite web|title=Rijeka i Zrinjski remizirali pod stijenama Kantride|url=http://www.nk-rijeka.hr/vijest/rijeka-i-zrinjski-remizirali-pod-stijenama-kantride/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}}{{cite web|title=Rijeka uveličala 100. rođendan NK Crikvenica!|url=http://www.nk-rijeka.hr/vijest/rijeka-uvelicala-100-rodendan-nk-crikvenica/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} but was again benched for a game after helping his team to the Cup quarter-finals. He at last debuted in the new season on 10 November and received a yellow in a devastating 0–5 loss against GNK Dinamo.{{cite web|title=Rijeka poražena protiv Dinama na Rujevici|url=http://www.nk-rijeka.hr/vijest/rijeka-porazena-protiv-dinama-na-rujevici/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} Following this, Petar was, along with Roberto Punčec, Zoran Kvržić and Lorenco Šimić, removed from the first team squad.{{cite web|title=HNK Rijeka – priopćenje|url=http://www.nk-rijeka.hr/vijest/hnk-rijeka-priopcenje/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} Seeing as Rijeka didn't have an active second squad and the players were too old to play in the youth teams and were so given a separate training regiment, the Croatian Football Syndicate filed an appeal against this decision on the grounds of every player having a right to train and play with the rest of their designated squad.{{cite web|title=Priopćenje za medije povodom priopćenja HNK Rijeka|url=https://www.huns.hr/hr/672/Priop%C4%87enje+za+medije+HUNS-a|work=Hrvatska udruga Nogometni sindikat|access-date=11 February 2020|language=Croatian}} However, since this was a commonplace practice in Croatian football, the appeal fell on deaf ears{{cite web|title=Odvjetnici suspendiranih igrača Rijeke dobili dovoljno materijala da se javnost ima čime zabavljati idućih mjeseci|url=https://www.vavikvjernakirija.com/l/odvjetnici-suspendiranih-igraca-rijeke-dobili-dovoljno-materijala-da-se-javnost-ima-cime-zabavljati-iducih-mjeseci/|work=Vavik vjerna Kirija|access-date=11 February 2020|language=Croatian}} and due to all this, Mamić was absent from the remaining five games of the half-season.

As the second half of the season approached, Petar's fate was still unknown. He had missed out on all the preseason warm-ups as well as the Cup quarter-finals. As for his suspended teammates, Roberto Punčec had left the club two weeks after their suspension{{cite web|title=HNK Rijeka i Roberto Punčec sporazumno raskinuli suradnju|url=http://www.nk-rijeka.hr/vijest/hnk-rijeka-i-roberto-puncec-sporazumno-raskinuli-suradnju/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} and had joined Sporting Kansas City ten days later,{{cite web|title=Ode i on "preko bare": Roberto Punčec nastavlja karijeru u Kansas Cityju|url=http://www.novilist.hr/Sport/NK-Rijeka/Ode-i-on-preko-bare-Roberto-Puncec-nastavlja-karijeru-u-Kansas-Cityju|work=Novi list|access-date=11 February 2020|language=Croatian}} Zoran Kvržić had transferred to Kayserispor on 9 January 2020{{cite web|title=Zoran Kvržić potpisao za Kayserispor: "Hvala klubu što mi je omogućio novi izazov"|url=http://www.nk-rijeka.hr/vijest/zoran-kvrzic-potpisao-za-kayserispor-hvala-klubu-sto-mi-je-omogucio-novi-izazov/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} and Lorenco Šimić's loan had been transferred to DAC Dunajská Streda on 6 February,{{cite web|title=Rijeka se riješila balasta, Lorenco Šimić i Mario Pavelić pronašli nove klubove|url=http://www.novilist.hr/Sport/NK-Rijeka/Rijeka-se-rijesila-balasta-Lorenco-Simic-i-Mario-Pavelic-pronasli-nove-klubove?meta_refresh=true|work=Novi list|access-date=11 February 2020|language=Croatian}} leaving Mamić the sole suspended player one round into the start of the second half of the season. Having returned left back Daniel Štefulj from his loan to NK Varaždin on 11 January,{{cite web|title=Daniel Štefulj ponovo u redovima Rijeke|url=http://www.nk-rijeka.hr/vijest/daniel-stefulj-ponovo-u-redovima-rijeke/|work=HNK Rijeka|access-date=11 February 2020|language=Croatian}} it had become obvious that HNK Rijeka had no intention of rehabilitating Mamić.{{cite web|title=Rijeka se rješava Petra Mamića, odlazi u klub iz HNL-a|url=https://www.germanijak.hr/vijesti/rijeka-se-rijesava-petra-mamica-odlazi-u-klub-iz-hnla/71445|work=Germanijak.hr|access-date=11 February 2020|language=Croatian}} A month after this development, on 10 February, two rounds into the season, Mamić was loaned out to NK Varaždin{{cite web|title=Rijeka poslala Petra Mamića na posudbu u Varaždin|url=http://www.novilist.hr/Sport/NK-Rijeka/Rijeka-poslala-Petra-Mamica-na-posudbu-u-Varazdin|work=Novi list|access-date=11 February 2020|language=Croatian}} and joined the team on the bench in the next round against NK Inter.{{cite web|title=Varaždin preokretom dolazi do pobjede golovima Benka i Petkovića|url=https://evarazdin.hr/nasim-krajem/varazdin-preokretom-dolazi-do-pobjede-golovima-benka-i-petkovica-382956/|work=eVaraždin.hr|date=15 February 2020|access-date=16 February 2020|language=Croatian}} He debuted full-time in the following game against NK Lokomotiva on 21 February and earned a yellow, becoming a starter then on.{{cite web|title=FOTO Lokomotiva riješila pitanje pobjednika s dva gola u prvom poluvremenu|url=https://evarazdin.hr/nasim-krajem/uzivo-varazdin-na-svom-terenu-vec-od-7-minute-gubi-od-lokomotive-383095/|work=eVaraždin.hr|date=21 February 2020|access-date=26 June 2020|language=Croatian}} After playing a friendly{{cite web|title=Varaždin isprobao sve igrače, a Bednja se pokazala kao "tvrd orah"|url=https://evarazdin.hr/nasim-krajem/varazdin-isprobao-sve-igrace-a-bednja-se-pokazala-kao-tvrd-orah-383119/|work=eVaraždin.hr|date=22 February 2020|access-date=26 June 2020|language=Croatian}} and two more league games{{cite web|title=Remi Slaven Belupa i Varaždina|url=https://nk-slaven-belupo.hr/remi-slaven-belupa-i-varazdina/|work=NK Slaven Belupo|access-date=26 June 2020|language=Croatian}} he earned yet another yellow{{cite web|title=Bod protiv Varaždina u posljednjim trenucima susreta|url=https://www.hnk-gorica.hr/vijesti/bod-protiv-varazdina-u-posljednjim-trenucima-susreta/365|work=HNK Gorica|access-date=26 June 2020|language=Croatian}} and was so absent from the next game due to accumulated cards.{{cite web|title=Samir Toplak na gostovanje u Osijek ide bez Benka, Mamića, Kolarića i Novoselca|url=https://evarazdin.hr/nasim-krajem/samir-toplak-na-gostovanje-u-osijek-ide-bez-benka-mamica-kolarica-i-novoselca-383368/|work=eVaraždin.hr|date=5 March 2020|access-date=26 June 2020|language=Croatian}} Mamić then scored his first goal for the team in a 3-1 friendly victory over NK Kustošija on 10 March.{{cite web|title=Prijateljski susret s Kustošijom generalna proba za Dinamo|url=https://evarazdin.hr/nasim-krajem/prijateljski-susret-s-kustosijom-generalna-proba-za-dinamo-383486/|work=eVaraždin.hr|date=10 March 2020|access-date=26 June 2020|language=Croatian}} Three days before the next league round, the Croatian Football Federation suspended all competitions under its jurisdiction due to the ongoing COVID-19 pandemic{{cite web|title=Prekid svih nogometnih natjecanja do 31. ožujka 2020.|url=https://hns-cff.hr/news/21241/prekid-svih-nogometnih-natjecanja-do-31-ozujka-2020/?fbclid=IwAR3EqxnhT1zv0l2XzgB8Jd3pAQIkTiWiIHcFzI6XYm2lc8fq1vIqp6NZDlE|work=HNS|access-date=26 June 2020|language=Croatian}} and the club soon followed suit suspending all senior team practice on 15 March.{{cite web|title=I treninzi seniorske momčadi NK Varaždin odgođeni do daljnjega|url=https://evarazdin.hr/nasim-krajem/i-treninzi-seniorske-momcadi-nk-varazdin-odgodeni-do-daljnjega-383581/|work=eVaraždin.hr|date=15 March 2020|access-date=26 June 2020|language=Croatian}}

Following relaxed pandemic measures, over six weeks after their suspension, senior team practice resumed on 27 April{{cite web|title=U ponedjeljak počinju grupni treninzi NK Varaždin pod vodstvom trenera Samira Toplaka|url=https://evarazdin.hr/nasim-krajem/u-ponedjeljak-pocinju-grupni-treninzi-nk-varazdin-pod-vodstvom-trenera-samira-toplaka-384266/|work=eVaraždin.hr|date=24 April 2020|access-date=26 June 2020|language=Croatian}} and Petar played in all three friendly warm up games.{{cite web|title=Varaždin s Lokomotivom odigrao drugu prijateljsku utakmicu na stadionu u Kranjčevićevoj|url=https://evarazdin.hr/nasim-krajem/varazdin-s-lokomotivom-odigrao-11-na-stadionu-u-kranjcevicevoj-384803/|work=eVaraždin.hr|date=23 May 2020|access-date=26 June 2020|language=Croatian}}{{cite web|title=Gorica svladala Varaždin rezultatom 5:1|url=https://www.hnk-gorica.hr/vijesti/gorica-svladala-varazdin-rezultatom-5-1/482|work=HNK Gorica|access-date=26 June 2020|language=Croatian}} He resumed the league along with the rest of the team on 6 June against GNK Dinamo{{cite web|title=Pobjeda Dinama i tri boda za nastavak HT Prve lige|url=https://gnkdinamo.hr/hr/Novosti/Clanak/pobjeda-dinama-i-tri-boda-za-nastavak-ht-prve-lige|work=GNK Dinamo|access-date=26 June 2020|language=Croatian}} and following a goalless draw{{cite web|title=Varaždin – Rijeka 0:0|url=http://www.nk-rijeka.hr/vijest/varazdin-rijeka-00-4/|work=HNK Rijeka|access-date=26 June 2020|language=Croatian}} scored his first league goal for the team on 16 June in a 3–2 victory over HNK Hajduk{{cite web|title=Split: Hajduk - Varaždin 2:3|url=https://hajduk.hr/vijest/split-hajduk-varazdin-2-3/12764|work=HNK Hajduk|access-date=26 June 2020|language=Croatian}} even earning himself a spot in {{Interlanguage link multi|Telesport's|hr|Telegram (portal)}} ideal XI of the league's 29th round.{{cite web|title=Igrač kola: Pa, ovaj… Mijo Caktaš|url=https://telesport.telegram.hr/hnl-statistika/igrac-kola-pa-ovaj-mijo-caktas/|work=Telesport|date=19 June 2020|access-date=26 June 2020|language=Croatian}} After yet another win,{{cite web|title=FOTO Obregon, Drožđek i Petković matirali Istru i donijeli Varaždinu vrlo važna tri boda|url=https://evarazdin.hr/nasim-krajem/uzivo-varazdinci-u-derbiju-zacelja-s-istrom-1961-traze-bodove-za-ostank-385377/|work=eVaraždin.hr|date=20 June 2020|access-date=26 June 2020|language=Croatian}} Mamić gave an assist to Jorge Obregón in a 1–0 victory over NK Inter on 25 June and was pronounced man of the match as well as earning a second spot in Telesport's ideal XI.{{cite web|title=VIDEO: Trube za ostanak odjekuju Varaždinom, trojac fantazista predvođen Toplakom ostavlja ih u HNL-u|url=https://sportske.jutarnji.hr/sn/nogomet/hnl/video-trube-za-ostanak-odjekuju-varazdinom-trojac-fantazista-predvoden-toplakom-ostavlja-ih-u-hnl-u-15004652|work=Sportske novosti|access-date=27 June 2020|language=Croatian}}{{cite web|title=Kastratijev efekt|url=https://telesport.telegram.hr/hnl-statistika/kastratijev-efekt/|work=Telesport|date=29 June 2020|access-date=30 June 2020|language=Croatian}} He played the remaining five games of the season as a starter,{{cite web|title=Varaždin se dobro branio od napada Lokomotive ali ipak izgubio 2:0|url=https://evarazdin.hr/nasim-krajem/varazdin-se-dobro-branio-od-napada-lokomotive-385564/|work=eVaraždin.hr|date=30 June 2020|access-date=25 August 2020|language=Croatian}} playing the last four full-time{{cite web|title=FOTO: Evo atmosfere sa sinoćnje tekme koja je "zabetonirala" ostanak|url=https://evarazdin.hr/fotogalerije/foto-evo-sinocnje-atmosfere-sa-stadiona-na-utakmici-koja-je-zabetonirala-ostanak-385643/|work=eVaraždin.hr|date=5 July 2020|access-date=25 August 2020|language=Croatian}}{{cite web|title=FOTO Domagoj Držođek nakon vrhunskog gola: "Dajemo sve za naše navijače i naš grad!"|url=https://evarazdin.hr/nasim-krajem/foto-domagoj-drzodek-nakon-vrhunskog-gola-dajemo-sve-za-nase-navijace-i-nas-grad-385885/|work=eVaraždin.hr|date=19 July 2020|access-date=25 August 2020|language=Croatian}}{{cite web|title=Varaždin nije uspio iznenaditi prvaka i izgubio na Maksimiru 2:0|url=https://evarazdin.hr/nasim-krajem/varazdin-nije-uspio-iznenaditi-prvaka-i-izgubio-u-maksimiru-20-385988/|work=eVaraždin.hr|date=24 July 2020|access-date=25 August 2020|language=Croatian}} and securing Varaždin's spot in the top tier of Croatian football for the next season in the third game.{{cite web|title=Varaždin u Gorici odigrao taktički odličnu utakmicu i pobijedio|url=https://evarazdin.hr/nasim-krajem/varazdin-u-gorici-odigrao-385752/|work=eVaraždin.hr|date=10 July 2020|access-date=25 August 2020|language=Croatian}}

Petar played in NK Varaždin's only preseason warm-up{{cite web|title=FOTO Tko je bio na generalki Varaždin - Slaven Belupo, posljednjoj provjeri pred novu sezonu?|url=https://evarazdin.hr/nasim-krajem/foto-tko-je-bio-na-generalki-varazdin-slaven-belupo-posljednjoj-provjeri-pred-novu-sezonu-386183/|work=eVaraždin.hr|date=9 August 2020|access-date=25 August 2020|language=Croatian}} and was expected to be permanently transferred to the club.{{cite web|title=Toplak: Bolje uzeti igrača koji je igrao u drugoj ligi nego onoga koji je u prvoj sjedio na klupi|url=https://www.24sata.hr/sport/toplak-bolje-uzeti-igraca-koji-je-igrao-u-drugoj-ligi-nego-onoga-koji-je-u-pvoj-ligi-sjedio-na-klupi-709312|work=24 Sata|access-date=25 August 2020|language=Croatian}} However, as the season progressed, Petar's loan was not extended amidst negotiations with NK Istra 1961.{{cite web|title=Donedavni mladi reprezentativac i dijete Dinama napušta Rujevicu, ali ostaje u Prvoj HNL|url=https://www.germanijak.hr/vijesti/donedavni-mladi-reprezentativac-i-dijete-dinama-napusta-rujevicu-ali-ostaje-u-prvoj-hnl/78662|work=Germanijak|access-date=11 September 2020|language=Croatian}} Ultimately his contract with HNK Rijeka was terminated on 10 September as negotiations with Istra fell through and talks of interest from Cracovia and some Romanian clubs surfaced.{{cite web|title=Rijeka raskinula ugovor s bivšim igračem Dinama, on bira između nekoliko ponuda|url=https://www.germanijak.hr/vijesti/rijeka-raskinula-ugovor-s-bivsim-igracem-dinama-on-bira-izmedju-dvije-ponude/78758|work=Germanijak|access-date=11 September 2020|language=Croatian}} Finally, Mamić reached an agreement with Ekstraklasa side Raków Częstochowa the following day on a two-year contract.{{cite web|title=Doznajemo: Petar Mamić nakon raskida s Rijekom ima novi klub|url=https://www.index.hr/sport/clanak/doznajemo-poljski-prvoligas-dovodi-bivseg-igraca-rijeke-stvara-duo-hrvatskih-bekova/2211765.aspx|work=Index.hr|access-date=11 September 2020|language=Croatian}}{{cite web|title=Petar Mamić nowym zawodnikiem Rakowa!

|url=https://rakow.com/aktualnosci/petar-mamic-nowym-zawodnikiem-rakowa-8437|work=Raków Częstochowa|access-date=12 September 2020|language=Polish}} Five rounds later, on 17 October, Mamić at last debuted on the bench.{{cite web|title=Raków wygodnie usadowił się w fotelu lidera!|url=http://gazetacz.com.pl/rakow-wygodnie-usadowil-sie-w-fotelu-lidera/|work=Gazeta Częstochowska|date=17 October 2020|access-date=23 December 2020|language=Polish}} Following this, however, Petar remained on the bench for the next two league rounds{{cite web|title=Ivi Golleador|url=http://gazetacz.com.pl/ivi-golleador/|work=Gazeta Częstochowska|date=25 October 2020|access-date=23 December 2020|language=Polish}}{{cite web|title=Remis we mgle|url=http://gazetacz.com.pl/remis-we-mgle/|work=Gazeta Częstochowska|date=8 November 2020|access-date=23 December 2020|language=Polish}} as well as the Round of 32 of the Polish Cup{{cite web|title=Zwycięstwo zgodnie z planem|url=http://gazetacz.com.pl/zwyciestwo-zgodnie-z-planem/|work=Gazeta Częstochowska|date=30 October 2020|access-date=23 December 2020|language=Polish}} before missing out on the next league game. Ultimately, Mamić finished the half-season on the bench in the remaining four games{{cite web|title=Zwycięstwo w męczarniach|url=http://gazetacz.com.pl/zwyciestwo-w-meczarniach/|work=Gazeta Częstochowska|date=29 November 2020|access-date=23 December 2020|language=Polish}}{{cite web|title=Koniec rekordowej serii Rakowa|url=http://gazetacz.com.pl/koniec-rekordowej-serii-rakowa/|work=Gazeta Częstochowska|date=5 December 2020|access-date=23 December 2020|language=Polish}}{{cite web|title=Zwycięstwo na pożegnanie z GIEKSA Areną|url=http://gazetacz.com.pl/zwyciestwo-na-pozegnanie-z-gieksa-arena/|work=Gazeta Częstochowska|date=13 December 2020|access-date=23 December 2020|language=Polish}}{{cite web|title=Raków "przezimuje" jako wicelider PKO Bank Polski Ekstraklasy!|url=http://gazetacz.com.pl/rakow-przezimuje-jako-wicelider-pko-bank-polski-ekstraklasy/|work=Gazeta Częstochowska|date=20 December 2020|access-date=23 December 2020|language=Polish}} as reports of his transfer to Podbeskidzie Bielsko-Biała surfaced.{{cite web|title=Petar Mamić trafi do Podbeskidzia Bielsko-Biała [NASZ NEWS]|url=https://www.meczyki.pl/newsy/mamic-trafi-do-podbeskidzia-nasz-news/157304-n|work=Meczyki.pl|access-date=23 December 2020|language=Polish}}

A little under three weeks after the first reports of his potential transfer to Podbeskidzie, Mamić's transfer was confirmed on 9 January 2021 on a contract to the end of the season with an option of extending it for an additional year{{cite web|title=PETAR MAMIĆ DOŁĄCZA DO GÓRALI!|url=https://tspodbeskidzie.pl/newsy/petar-mamic-dolacza-do-gorali|work=TS Podbeskidzie Bielsko-Biała|access-date=9 January 2021|language=Polish}} and immediately debuted for the team the same day playing the first half of its first warm-up game before the continuation of the season against Czech side SFC Opava.{{cite web|title=[SPARING]: TS PODBESKIDZIE - SFC OPAWA 1:0|url=https://tspodbeskidzie.pl/newsy/sparing-ts-podbeskidzie-sfc-opawa-10|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}} He played the next friendly and then joined the team on trials in Poreč where he played in both remaining friendlies.{{cite web|title=[SPARING]: MSK ŻYLINA - PODBESKIDZIE 1:2|url=https://tspodbeskidzie.pl/newsy/sparing-msk-zylina-podbeskidzie-12|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=[SPARING]: TS PODBESKIDZIE - OLIMPIJA LUBLANA 2:0|url=https://tspodbeskidzie.pl/newsy/sparing-ts-podbeskidzie-olimpija-lublana-20|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=[SPARING]: LEWSKI - PODBESKIDZIE 1:0|url=https://tspodbeskidzie.pl/newsy/sparing-lewski-podbeskidzie-10|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}} Upon returning to Poland, Petar made his Ekstraklasa debut on 31 January, playing the full 90 minutes and earning a yellow card in a 1–0 victory over Legia Warsaw.{{cite web|title=PODBESKIDZIE BIELSKO-BIAŁA 1-0 LEGIA WARSZAWA - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/Podbeskidzie_Bielsko-Biala_-_Legia_Warszawa.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}} He played the following four matches full-time before being substituted in the last minutes of the next one.{{cite web|title=PODBESKIDZIE BIELSKO-BIAŁA 2-1 GÓRNIK ZABRZE - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/Podbeskidzie_Bielsko-Biala_-_Gornik_Zabrze.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=CRACOVIA 1-1 PODBESKIDZIE BIELSKO-BIAŁA - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/Cracovia_-_Podbeskidzie_Bielsko-Biala.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=PODBESKIDZIE BIELSKO-BIAŁA 1-1 JAGIELLONIA BIAŁYSTOK - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/Podbeskidzie_Bielsko-Biala_-_Jagiellonia_Bialystok.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=RAKÓW CZĘSTOCHOWA 1-0 PODBESKIDZIE BIELSKO-BIAŁA - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/Rakow_Czestochowa_-_Podbeskidzie_Bielsko-Biala.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=PODBESKIDZIE BIELSKO-BIAŁA 2-2 LECHIA GDAŃSK - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/Podbeskidzie_Bielsko-Biala_-_Lechia_Gdansk.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}} He then received a concussion on 15 March in the following game against Stal Mielec, forcing an injury substitution after which he missed out on the next two league games.{{cite web|title=STAL MIELEC 2-1 PODBESKIDZIE BIELSKO-BIAŁA - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/PGE_FKS_Stal_Mielec_-_Podbeskidzie_Bielsko-Biala_1.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}} Petar returned in a friendly on 26 March but played for only part of the second half and was then benched for the following two league games.{{cite web|title=[SPARING] TS PODBESKIDZIE - MFK KARVINA|url=https://tspodbeskidzie.pl/newsy/sparing-ts-podbeskidzie-mfk-karvina|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}} He at last returned to the league pitch in style on 20 April, giving an assist to Rafał Janicki for the team's opening goal and equalizer before being substituted out in an eventual 3–4 loss to Śląsk Wrocław.{{cite web|title=ŚLĄSK WROCŁAW 4-3 PODBESKIDZIE BIELSKO-BIAŁA - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/26.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}} Even though he remained a starter, Petar did not play full-time in any of the remaining four league matches but did give an assist on 8 May to Jakub Hora for the leading goal in an eventual 1–1 tie with Wisła Płock.{{cite web|title=PODBESKIDZIE BIELSKO-BIAŁA 1-0 LECH POZNAŃ - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/Podbeskidzie_Bielsko-Biala_-_Lech_Poznan.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=PIAST GLIWICE 2-0 PODBESKIDZIE BIELSKO-BIAŁA - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/28_1.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=PODBESKIDZIE BIELSKO-BIAŁA 1-1 WISŁA PŁOCK - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/29_1.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=LEGIA WARSZAWA 1-0 PODBESKIDZIE BIELSKO-BIAŁA - RAPORT STATYSTYCZNY|url=https://tspodbeskidzie.pl/static/upload/store/RaportyStatystyczne/Legia_Warszawa_-_Podbeskidzie_Bielsko-Biala.pdf|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}} With Podbeskidzie ending up relegated and Petar being one of the club's more expensive players, they amicably agreed not to extend his contract, leaving him a free agent on 18 June.{{cite web|title=DZIĘKUJEMY ZA GRĘ W PODBESKIDZIU!|url=https://tspodbeskidzie.pl/newsy/dziekujemy-za-gre-w-podbeskidziu|work=TS Podbeskidzie|access-date=8 July 2021|language=Polish}}{{cite web|title=Petar Mamić bez kluba, za Germanijak otkrio kako je boriti se za ostanak u Poljskoj|url=https://www.germanijak.hr/nogomet/vijesti/petar-mamic-bez-kluba-za-germanijak-otkrio-kako-je-boriti-se-za-ostanak-u-poljskoj/87558|work=Germanijak|access-date=8 July 2021|language=Croatian}}

A week after the 2021 summer transfer window had closed, news surfaced that Petar was returning to the Croatian First Football League and joining newly promoted NK Hrvatski Dragovoljac in yet another bid to avoid relegation.{{cite web|title=Ipak zaposlen: Petar Mamić se vraća u 1.HNL|url=https://www.germanijak.hr/nogomet/vijesti/ipak-zaposlen-petar-mamic-se-vraca-u-1hnl/90410|work=Germanijak|access-date=12 September 2021|language=Croatian}}

Mamić debuted for the Croatian under-14 team on 26 May 2010 playing a friendly against Bavaria. Later that year he joined the under-15 team and played six friendlies throughout the season. After a short hiatus he joined the national under-16 side eventually competing in eight friendlies.{{cite web|title=Petar Mamić|url=http://hns-cff.hr/players/21195/petar-mamic/utakmice/|work=HNS|access-date=21 June 2014|language=Croatian}}

Mamić made his debut for the Croatia under-17 team on 1 August 2012 in a friendly against the Czech Republic scoring his first ever international goal only two days later in a friendly against Serbia.{{cite web|title=Petar Mamić|url=http://hns-cff.hr/players/21195/petar-mamic/utakmice/|work=HNS|access-date=21 June 2014|language=Croatian}} Mamić was selected for the 2013 UEFA European Under-17 Championship qualification team. He played a good first game against Israel receiving a yellow card {{cite web|title=U-17: Mladi reprezenativci Hrvatske svladali Izrael 4:2|url=http://www.novilist.hr/Sport/Nogomet/U-17-Mladi-reprezenativci-Hrvatske-svladali-Izrael-4-2?articlesrclink=related|work=Novi List|access-date=21 June 2014|language=Croatian}}

only to score his first competitive goal in the second match against Kazakhstan.{{cite web|title=Mamić Hrvatskoj otvorio put do pobjede nad Kazahstanom|url=http://www.vecernji.hr/reprezentacija/mamic-hrvatskoj-otvorio-put-do-pobjede-nad-kazahstanom-464943|work=Večernji List|access-date=21 June 2014|language=Croatian}} After qualifying for the Elite round Mamić scored the first goal against Spain after a corner kick in the 45' minute eventually leading to Croatia's victory.{{cite web|title=Kakva pobjeda: Hrvatska U17 reprezentacija svladala Španjolsku s čak dva igrača manje|url=http://www.dnevno.hr/sport/nogomet/82113-kakva-pobjeda-hrvatska-u17-reprezentacija-svladala-spanjolsku-s-cak-dva-igraca-manje.html|work=Dnevno.hr|access-date=21 June 2014|language=Croatian}} Petar played the rest of the qualifications qualifying for the European Championship and after two goalless games received a red card in the final game against Ukraine.{{cite web|title=Victory in vain for Croatia|url=https://www.uefa.com/under17/news/0252-0cdc9de28b31-316f9d333ca8-1000--victory-in-vain-for-croatia/|work=UEFA|date = 11 May 2013|access-date=21 June 2014}} In October Mamić, having missed the first game of the World Cup, played a very good game against Panama{{cite web|title=SP U-17: Hrvatska - Panama 1:0|url=http://www.glasistre.hr/vijesti/sport/sp-u-17-hrvatska---panama-1-0-427429|work=Glas Istre|access-date=21 June 2014|language=Croatian}} and played a somewhat weaker game against Uzbekistan eventually being replaced by Ivan Fiolić.{{cite web|title=Hrvatska izgubila od Uzbekistana i stigla na korak od ispadanja!|url=http://www.vecernji.hr/reprezentacija/hrvatska-izgubila-od-uzbekistana-i-stigla-na-korak-od-ispadanja-632547|work=Večernji List|access-date=21 June 2014|language=Croatian}}

Besides playing three friendlies with the Croatian under-18 team{{cite web|title=Hrvatska - Brazil 1:1|url=http://hns-cff.hr/matches/240474/hrvatska-brazil-11/|work=HNS|access-date=13 November 2015|language=Croatian}}{{cite web|title=Hrvatska U-18 pobijedila je u prijateljskoj utakmici svoje domaćine, odgovarajuću izabranu vrstu Engleske|url=http://hns-cff.hr/matches/241163/engleska-hrvatska-12/|work=HNS|access-date=21 June 2014|language=Croatian}}{{cite web|title=Nakon pobjede u ponedjeljak, hrvatska selekcija U-18 odigrala je još jednu utakmicu protiv svojih vršnjaka iz Engleske i ponovno pobijedila|url=http://hns-cff.hr/matches/241164/engleska-hrvatska-12/|work=HNS|access-date=21 June 2014|language=Croatian}} Mamić was called in for the Croatia national under-19 football team and debuted on 12 August 2013 in a friendly against Azerbaijan playing 79 minutes before being replaced by Luka Capan.{{cite web|title=Hrvatska U-19 selekcija odigrala je neriješeno u prijateljskom susretu s vršnjacima iz Azerbajdžana|url=http://hns-cff.hr/matches/192078/hrvatska-azerbajdzan-11/|work=HNS|access-date=21 June 2014|language=Croatian}} Mamić was also called in for the 2015 UEFA European Under-19 Championship qualification{{cite web|title=Vulć objavio popis: S juniorima Dinama i Hajduka u borbu za Euro|url=http://www.index.hr/sport/clanak/vulic-objavio-popis-s-juniorima-dinama-i-hajduka-u-borbu-za-euro/774404.aspx|work=Index.hr|access-date=30 September 2014|language=Croatian}} playing full-time in all three games earning a yellow card in the third game against Turkey and qualifying for the Elite Round.{{cite web|title=U Dugopolju pao Island Druga pobjeda Hrvatske U-19 za osiguran nastavak kvalifikacija|url=http://hns-cff.hr/news/5193/roguljic-pogodio-za-pobjedu-hrvatske-u-19/|work=HNS|access-date=7 October 2014|language=Croatian}}{{cite web|title=Uspješan start u Sinju Roguljić pogodio za pobjedu Hrvatske U-19|url=http://hns-cff.hr/news/5205/druga-pobjeda-hrvatske-u-19-za-osiguran-nastavak-kvalifikacija/|work=HNS|access-date=9 October 2014|language=Croatian}}{{cite web|title=Remi s Turskom Hrvatska U-19 potvrdila prvo mjesto u Skupini 3|url=http://hns-cff.hr/news/5235/hrvatska-u-19-potvrdila-prvo-mjesto-u-skupini-3/|work=HNS|access-date=13 October 2014|language=Croatian}} Mamić played the first and third game in the Elite Round with both ending in draws but ultimately failed to qualify for the 2015 UEFA European Under-19 Championship.{{cite web|title=Hrvatska U-19 uzela bod protiv Italije|url=http://hns-cff.hr/news/9655/hrvatska-u-19-uzela-bod-protiv-italije/|work=HNS|access-date=31 March 2015|language=Croatian}}{{cite web|title= Italy-Croatia 2:2|url=https://www.uefa.com/under19/match/2015849--italy-vs-croatia/|work=UEFA|access-date=31 March 2015}}{{cite web|title=Hrvatska zaključila Elitno kolo remijem sa Škotima|url=http://hns-cff.hr/news/9675/hrvatska-zakljucila-elitno-kolo-remijem-sa-skotima/|work=HNS|access-date=31 March 2015|language=Croatian}}{{cite web|title=Scotland-Croatia 1:1|url=https://www.uefa.com/under19/match/2015878--scotland-vs-croatia/|work=UEFA|access-date=31 March 2015}}

Mamić participated in three day trials for the Croatia national under-21 football team in Sveti Martin na Muri and debuted for the team on 23 March 2017, playing the last half hour, in a friendly 3–0 win over Slovenia.{{cite web|title=Hrvatska U-21 svladala Sloveniju|url=http://hns-cff.hr/news/16006/hrvatska-u-21-svladala-sloveniju-3-0/|work=HNS|access-date=26 August 2017|language=Croatian}} He joined the team for the autumn 2017 part of the 2019 UEFA European Under-21 Championship qualification and debuted in the competition as a last-minute substitute in a 5–1 victory over the Czech Republic on 9 October 2017.{{cite web|title=Sjajno izdanje Hrvatske U-21 za preuzimanje vodstva|url=http://hns-cff.hr/news/16969/sjajno-izdanje-hrvatske-u-21-za-preuzimanje-vodstva/|work=HNS|access-date=26 August 2017|language=Croatian}} He accompanied the team for the entire qualifying tournament{{cite web|title=AKCIJA ČEŠKA: Nenad Gračan: "Nismo kompletni, ali smo odlučni"|url=http://hns-cff.hr/news/17732/nenad-gracan-nismo-kompletni-ali-smo-odlucni/|work=HNS|access-date=1 April 2018|language=Croatian}}{{cite web|title=GOSTOVANJE KOD BJELORUSIJE: IZBORNIK GRAČAN OBJAVIO POPIS HRVATSKE U-21|url=http://hns-cff.hr/news/18619/izbornik-gracan-objavio-popis-hrvatske-u-21/|work=HNS|access-date=26 September 2018|language=Croatian}}{{cite web|title=ODLUČUJUĆI SUSRETI ZA HRVATSKU U-21: POPIS IZBORNIKA GRAČANA ZA SUSRETE S GRČKOM I SAN MARINOM|url=https://hns-cff.hr/news/18862/popis-izbornika-gracana-za-susrete-s-grckom-i-san-marinom/|work=HNS|access-date=24 March 2019|language=Croatian}} and played full-time in the last game against San Marino on 15 October 2018.{{cite web|title=ZASLUŽENO SLAVLJE: VIDEO: HRVATSKA U-21 OSIGURALA PLASMAN NA EP!|url=https://hns-cff.hr/matches/26833211/san-marino-hrvatska-0-4/|work=HNS|access-date=24 March 2019|language=Croatian}} He played the team's following match, a friendly against France on 15 November 2018,{{cite web|title=MLADI VATRENI U ZEMLJI SVJETSKIH PRVAKA: VIDEO: DOBAR NASTUP HRVATSKE U-21 U FRANCUSKOJ, NERIJEŠENO S DOMAĆINOM|url=https://hns-cff.hr/matches/29771221/francuska-hrvatska-2-2/|work=HNS|access-date=24 March 2019|language=Croatian}} and another against Italy on 25 March 2019.{{cite web|title=VIDEO: POVRATAK HRVATSKE U-21 U ITALIJI, HALILOVIĆ I KALAICA ZA REMI|url=https://hns-cff.hr/matches/30420485/italija-hrvatska-2-2/|work=HNS|access-date=21 April 2019|language=Croatian}} He was named in the preliminary squad for the Euro{{cite web|title=25 IGRAČA: IZBORNIK GRAČAN OBJAVIO POPIS KANDIDATA ZA EURO U-21|url=https://hns-cff.hr/news/20008/izbornik-gracan-objavio-popis-kandidata-za-euro-u-21/|work=HNS|access-date=30 June 2019|language=Croatian}} but eventually missed the cut due to osteomyelitis and so didn't accompany the team for two friendlies as well as the entire tournament.{{cite web|title=Robert Murić na popisu putnika reprezentacije Hrvatske (U-21) za EURO|url=http://www.nk-rijeka.hr/vijest/robert-muric-na-popisu-putnika-reprezentacije-hrvatske-u-21-za-euro/|work=HNK Rijeka|access-date=30 June 2019|language=Croatian}}

A player of great motor functions and speed, Mamić has been described as the best left-back of his generation in the GNK Dinamo Zagreb Academy.{{cite web|title='U DINAMU NISAM PROŠAO ZATO ŠTO SAM MAMIĆ' Do prije godinu dana bio je predodređen za veliku karijeru, a onda je završio u drugoj talijanskoj ligi|url=https://sportske.jutarnji.hr/nogomet/u-dinamu-nisam-prosao-zato-sto-sam-mamic-do-prije-godinu-dana-bio-je-predodreden-za-veliku-karijeru-a-onda-je-zavrsio-u-drugoj-talijanskoj-ligi/5550767/|work=Sportske novosti|date=26 January 2017|access-date=21 April 2019|language=Croatian}} Exclusively a left field player, his natural role is a defensive back with occasional bursts along the line towards the opposing goal in which he can center or even shoot.{{cite web|title='U DINAMU NISAM PROŠAO ZATO ŠTO SAM MAMIĆ' Do prije godinu dana bio je predodređen za veliku karijeru, a onda je završio u drugoj talijanskoj ligi|url=http://www.novilist.hr/Sport/NK-Rijeka/PETAR-MAMIC-U-BIJELOM-DRESU-Sharbini-je-bio-neugodan-Acostyja-najteze-cuvati?meta_refresh=true|work=Novi list|access-date=21 April 2019|language=Croatian}} He is an admirer of Andrew Robertson but doesn't try to emulate anyone's specific style.{{cite web|title='U DINAMU NISAM PROŠAO ZATO ŠTO SAM MAMIĆ' Do prije godinu dana bio je predodređen za veliku karijeru, a onda je završio u drugoj talijanskoj ligi|url=http://www.novilist.hr/Sport/NK-Rijeka/Zelim-da-se-racuna-na-mene-spreman-sam-podnijeti-pritisak-nakon-odlaska-Zute?meta_refresh=true|work=Novi list|access-date=21 April 2019|language=Croatian}} He is most at home playing in tandem with a player in front who can take up finishing roles, either a left midfielder like Alexander Gorgon in HNK Rijeka{{cite web|title=HAJDUK RAZOTKRIO SLABOSTI Gdje su nestali zaštitni znakovi Miškovićeve Rijeke: trka, agresija i duel igra?|url=http://novilist.hr/Sport/NK-Rijeka/HAJDUK-RAZOTKRIO-SLABOSTI-Gdje-su-nestali-zastitni-znakovi-Miskoviceve-Rijeke-trka-agresija-i-duel-igra?meta_refresh=true|work=Novi list|access-date=21 April 2019|language=Croatian}} or a left winger like Domagoj Bradarić in the Croatia national under-21 football team.{{cite web|title=Igrač kola: Domagoj Bradarić|url=https://telesport.telegram.hr/hnl-statistika/igrac-kola-domagoj-bradaric/|work=Telesport|date=12 March 2019|access-date=21 April 2019|language=Croatian}}

Petar, just like fellow players Niko Kranjčar{{cite web|title=MIOC-u treće krilo za 43. rođendan|url=http://www.jutarnji.hr/mioc-u-trece-krilo-za-43--rodendan/217399|work=Jutarnji list |language=Croatian |access-date=21 June 2014}} and Andrej Kramarić,{{cite web|title=U modi su učenici MIOC-a|url=http://www.jutarnji.hr/u-modi-su-ucenici-mioc-a/301226/|work=Jutarnji list |language=Croatian |access-date=21 June 2014}} graduated, in 2014, from the prestigious XV Gymnasium in Zagreb.{{cite web|title=Nogometni Petar Pan: Nije da igram zato što sam Mamićev rođak|url=https://www.vecernji.hr/premium/nogometni-petar-pan-nije-da-igram-zato-sto-sam-mamicev-rodjak-532231|work=Večernji list|access-date=1 April 2018|language=Croatian}} He is currently enrolled in the Faculty of Economics and Business of the University of Zagreb{{cite web|title=Priča o Divu iz predgrađa: Coutinho iz Šiljakovine predvodi Inter|url=https://gol.dnevnik.hr/clanak/rubrika/nogomet/prica-o-divu-iz-predgradja-coutinho-iz-siljakovine-predvodi-inter---499567.html|work=Gol.hr|access-date=1 April 2018|language=Croatian}} and is working on his master's thesis in accounting titled "Taxation of Athletes in Croatia".{{cite web|title='POREZNIK' U KOPAČKAMA SJAJNO ISKORISTIO PAUZU I OTKRIO ZAŠTO JE ZAPRAVO MORAO NAPUSTITI RUJEVICU Lijevi bek iz Dinamove škole ustalio se kod Toplaka i s ostatkom ekipe bio hit drugog dijela sezone|url=https://sportske.jutarnji.hr/sn/nogomet/hnl/poreznik-u-kopackama-sjajno-iskoristio-pauzu-i-otkrio-zasto-je-zapravo-morao-napustiti-rujevicu-15010768|work=Sportske novosti|access-date=25 August 2020|language=Croatian}}

His father Ivica ({{IPA|sh|ǐʋit͡sä|pron}}) played for Dinamo's cadets along with football coach Nikola Jurčević{{cite web|title=Jurčević otkrio kako je pobijedio Hajduka na Poljudu|url=https://slobodnadalmacija.hr/sport/domaci-nogomet/clanak/id/543380/jurcevic-otkrio-kako-je-pobijedio-hajduka-na-poljudu|work=Slobodna Dalmacija|date=25 April 2018|access-date=30 June 2019|language=hr}} who is Petar's confirmation sponsor.{{cite web|title=NESVAKIDAŠNJA SITUACIJA NA TERENIMA HNL-A! KUM SE NAMJERIO NA SVOJE KUMČE 'Tek je stigao, mogao bih mu malo zapapriti, bit ću posebno motiviran'|url=https://sportske.jutarnji.hr/nogomet/hnl/nesvakidasnja-situacija-na-terenima-hnl-a-kum-se-namjerio-na-svoje-kumce-tek-je-stigao-mogao-bih-mu-malo-zapapriti-bit-cu-posebno-motiviran/7190886/|work=Sportske novosti|date=30 March 2018|access-date=1 April 2018|language=Croatian}} He is also a distant relation of football manager brothers Zoran and Zdravko Mamić as both families trace routes to the village of Zidine.{{cite web|title=Nogometni Petar Pan: Nije da igram zato što sam Mamićev rođak|url=https://www.vecernji.hr/premium/nogometni-petar-pan-nije-da-igram-zato-sto-sam-mamicev-rodjak-532231|work=Večernji list|access-date=1 April 2018|language=Croatian}}

Petar participated on 14 August 2021 in a charitable event organized by Serbian owned Croatian gambling company Germania Sport by betting, correctly, on a humanitarian ballot on the outcome of five games and winning 4220 Kuna for the Orphanage in Nazor's Street in Zagreb.{{cite web|title=Humanitarni listić u podne: Petar Mamić tipuje za Nazorovu|url=https://www.germanijak.hr/kladionica/vijesti/humanitarni-listic-u-podne-petar-mamic-tipuje-za-nazorovu/89574|work=Germanijak|access-date=12 September 2021|language=Croatian}}

Dinamo Zagreb

• Prva HNL: 2013–14, 2015–16
• Croatian Cup: 2015–16
• Croatian Super Cup runner-up: 2014

Rijeka

• Croatian Cup: 2018–19
• Croatian Super Cup runner-up: 2019

Žalgiris

• A Lyga: 2022
• Lithuanian Cup: 2022
• Lithuanian Supercup: 2023

{{Reflist|group=note}}

{{reflist|30em}}

• {{CFF player|21195/petar-mamic}}
• {{Soccerway|petar-mami/273284}}
• [http://povijest.gnkdinamo.hr/popis-igra%C4%8Da/petar-mami%C4%87.html/ Petar Mamić] at GNK Dinamo Zagreb
• [http://www.nk-rijeka.hr/player/petar-mamic/ Petar Mamić] at HNK Rijeka

{{HŠK Zrinjski Mostar squad}}

{{DEFAULTSORT:Mamic, Petar}}

Category:1996 births

Category:Living people

Category:Footballers from Zagreb

Category:Men's association football fullbacks

Category:Croatian men's footballers

Category:GNK Dinamo Zagreb II players

Category:GNK Dinamo Zagreb players

Category:NK Lokomotiva Zagreb players

Category:Frosinone Calcio players

Category:NK Inter Zaprešić players

Category:HNK Rijeka players

Category:NK Varaždin (1931–2015) players

Category:Raków Częstochowa players

Category:Podbeskidzie Bielsko-Biała players

Category:NK Hrvatski Dragovoljac players

Category:FK Žalgiris players

Category:CFR Cluj players

Category:HŠK Zrinjski Mostar players

Category:Second Football League (Croatia) players

Category:First Football League (Croatia) players

Category:Croatian Football League players

Category:Ekstraklasa players

Category:A Lyga players

Category:Liga I players

Category:Premier League of Bosnia and Herzegovina players

Category:Croatian expatriate men's footballers

Category:Expatriate men's footballers in Italy

Category:Croatian expatriate sportspeople in Italy

Category:Expatriate men's footballers in Poland

Category:Croatian expatriate sportspeople in Poland

Category:Expatriate men's footballers in Lithuania

Category:Croatian expatriate sportspeople in Lithuania

Category:Expatriate men's footballers in Romania

Category:Croatian expatriate sportspeople in Romania

Category:Expatriate men's footballers in Bosnia and Herzegovina

Category:Croatian expatriate sportspeople in Bosnia and Herzegovina

Category:21st-century Croatian sportsmen