In April 2010, in a friendly match between the national teams of Serbia and Japan (3:0), Fejsa injured his anterior cruciate ligaments, after which he spent more than a year out of the field, and he played again only at the end of the 2010/11 season.

He showed good form at the beginning of 2011–12 season, and had impressive performances during the early stages of Champions League Groups.

In February 2013, when Leonardo Jardim was sacked by Olympiacos due to the crowds dismay because of the playing style of the team, coach Míchel was hired and he immediately made Fejsa one of the starters.

[6][7] He made decent appearances, despite being benched for most of the season and he was called back to Serbia national football team for the 2014 FIFA World Cup qualification.

[19] Fejsa made his senior debut for the Serbia national team under the guidance of head coach Javier Clemente with a substitute appearance during the rescheduled UEFA Euro 2008 qualifier at home against Kazakhstan on 24 November 2007.

[21] He earned a total of 25 caps (no goals scored)[22] and his final international was a June 2019 European Championship qualification match away against Ukraine.