In his first season with Aarhus, Grahn enjoyed great success appearing in 22 league matches and scoring 8 goals and providing 13 assists as the clubs playmaker.
Grahn got off to a great start with Odense scoring six goals in 15 league matches and helped the Danish club to an impressive run in the 2006–07 UEFA Cup.
At the end of the season, Gimnàstic was relegated to the Spanish Second Division, and Grahn was sent on loan to Hertha BSC in Germany.
[4] Grahn was so disappointed about his own performances and lack of success at Randers FC that he offered to leave the club in November 2009.
[6][7] During January 2012, it was reported that Grahn was close to agreeing to terms with New York Red Bulls in Major League Soccer.
[11] In August 2014 he was persuaded to play for Gentofte-Vangede IF in the Danish 2nd Division East by head coach Søren Fjorting whom Grahn knew from their past at Lyngby Boldklub.