 Matthews attended the University of Southern California and played for the Trojans from 2004 to 2008 under head coach Pete Carroll.Though he was the son of an All-Pro NFL linebacker, he entered USC as an unheralded, walk-on student athlete.During his first season, USC's 2004 BCS National Championship, he played only on the scout team and turned down several playing opportunities during garbage time during the fourth quarters of games to preserve his redshirt status and remaining seasons of NCAA eligibility.