[1] In the following 2013–14 season, Kosović scored his first goal in UEFA competitions, finding the back of the net in a 4–1 away win over Maltese club Hibernians on 4 July 2013.

[5] Led by his former manager Nebojša Vignjević, Kosović was a member of the team that won two major trophies (Magyar Kupa and Szuperkupa).

He eventually returned to Standard Liège in the 2015 winter transfer window, but failed to make any competitive appearance for their first team.

[8] In the following 2016–17 campaign, Kosović recorded 22 appearances and scored three goals in all competitions (league and cup), as Partizan won the double.

On 29 May 2016, Kosović made his full international debut for Montenegro, coming on as a substitute in a 1–0 friendly loss away against Turkey.