Answer
Mathieu played for Toulouse and Sochaux from 2003 to 2010. He started his career at Toulouse in 2003 and made his debut in the Ligue 1 on 20 September 2003. He played for Toulouse for seven seasons, making over 100 appearances and scoring 13 goals. In 2010, he moved to Sochaux and played for the club for two seasons, making over 50 appearances and scoring five goals.