Matthew Stephen Leinart (born May 11, 1983) is an American former professional football quarterback who played in the National Football League (NFL) for seven seasons. He played college football for the USC Trojans, where he won the Heisman Trophy and led his team to an undefeated season as a junior. Selected tenth overall by the Arizona Cardinals in the 2006 NFL draft, Leinart primarily served as Kurt Warner's backup for four seasons. He spent his final three seasons in a backup role for the Houston Texans and the Oakland Raiders. Leinart was…