He"s nicknamed Elaka Månz (Mean Månz), because of his tackles that often generated yellow cards. Club Östers IF
Born and raised in Växjö, Karlsson played youth level football for both Växjö Norra IF and later Östers IF. He got promoted to the first team of Östers IF in 2008, when they played in Division 1. He managed to help the team advance to Allsvenskan for the 2013 season, in wich he played 28 games and scored two goals.
Östers IF got relegated to Superettan the same year.
Karlsson wanted to continue playing first tier football, so he decided to move from Växjö to play with Åtvidabergs FF for the 2014 season. He signed a three-year-long contract with the club
His first goal for Åtvidabergs FF came against Gefle IF on April 21, 2014. Östers IF
Division 1 Södra: 2009