Career
Born in Trebinje, Gaćinović started playing football at his hometown club Leotar, before joining the youth academy of Vojvodina. On 18 May 2013, Gaćinović scored his first senior goal in a 3–2 home league victory over Radnički Niš. He was also the club"s top league scorer in the 2014-2015 season with 11 goals.
In the summer of 2015, Gaćinović moved to Germany and signed with Eintracht Frankfurt.
Gaćinović played for Bosnia and Herzegovina at Under-17 level, before eventually choosing to represent Serbia at Under-19 level Furthermore, Gaćinović scored an equalizer against Portugal in the 85th minute of the semi-final.
He also appeared at the 2014 Union of European Football Associations European Under-19 Championship. Gaćinović took part at the 2015 Fédération internationale de football association U-20 World Cup, winning the gold medal.