Originally from Bosnia, Nosic has a background in boxing. Starting the sport quite late, he would go on to become the Bosnian under 18's National Boxing Championships gold medalist after only a few months of training. Going on to represent Bosnia at the European Championships, he lost in a bout to future Olympic medalist Ben Whittaker via stoppage in that tournament.

Due to economic difficulties in Bosnia, after graduating highschool, he and his friend moved to Cork, Ireland where he would work as a kitchen porter then customer service agent, while also training at Brian Dillon's Amateur Boxing Club. Nosic went on to represent Dillon’s ABC in the Irish U22's National Championships, the Munster Championships, the Celtic Box Cup and, eventually the Irish Elite Championships. Along the way, he fought some of the country’s top names at light-heavyweight and heavyweight, including Tommy Hyde, Tony Browne and the late Kevin Sheehy.

Upon returning to Bosnia in 2020, Nosic began training at the Boksacki Klub Kralj Tomislav, in Capljina with his longtime friend Bosko Misic, under whose coaching and direction he had boxed to several national championships before his move to Ireland.