The Indianapolis Colts have ruled out five starters for Sunday's game at Oakland, with injuries to defensive end Robert Mathis leaving the team without any of its first-string defensive linemen from the start of training camp. The Colts on Saturday decided Mathis and safety Antoine Bethea would not play against the Raiders, team spokesman Craig Kelley said. The team had already listed receiver Marvin Harrison (bruised left knee), defensive tackle Raheem Brock (ribs) and right tackle Ryan Diem (knee) as out for Sunday. Mathis (sprains to both knees) and Bethea (sprained left knee) were injured during last Sunday's 44-20 rout in Baltimore. Neither finished the game, but most of the Colts starters were pulled midway through the third quarter.