Career
He started his career in Ullern, joining Football Club Lyn Oslo in 2007. He made his first team debut on 14 April 2007 against Fredrikstad, and played twenty Norwegian Premier League games in his first season, most of them as a starter. On 1 February 2010 Knudtzon signed a three year contract with Lillestrøm, and will be reunited with his former coach Henning Berg
His first season with LSK was one to forget as Knudtzon struggled with form and lack of confidence, never adapting to the more physical style of football Lillestrøm are known foreign
Knudtzon has however made an impressive start to the 2011 season, scoring twice and playing very well in the opening stages of the season.