Brašanac represented his country at all youth international levels, collecting more than 35 appearances, before making his senior team debut in 2015.
[5] He made his first appearance of the new season on 4 September 2010, replacing Saša Ilić in a 2–0 home league victory over Hajduk Kula.
On 8 December 2010, Brašanac made his UEFA Champions League debut in a 1–3 away loss to Arsenal at Emirates Stadium, coming on as an injury-time substitute for Almami Moreira.
After a season-long loan, Brašanac returned to Partizan, but was rarely chosen to play in the first half of the 2012–13 campaign, making only two national cup appearances.
Brašanac netted his first goal for the club on 6 March 2013, scoring directly from a corner kick in a 4–0 away league win over BSK Borča.
[10] After fully recovering, Brašanac returned to the starting lineup after winter break, helping Partizan win the championship.
In the 2015–16 season, Brašanac was an undisputed starter for Partizan, recording 40 appearances and scoring four goals in all competitions, as the club won the domestic cup after five years.
[11] He made his official debut for the Andalusian side on 11 September 2016, playing the full 90 minutes and receiving a yellow card in a 3–2 away win against Valencia.