University of Southern California running back Marc Tyler dislocated his left shoulder in the third quarter of the Trojans' 30-9 win over Cal at AT&T Park on Thursday and could be out an extended period of time. Tyler, a redshirt senior, suffered the injury on the first play of the second half, when he was tackled 2 yards behind the line of scrimmage by Cal linebacker Aaron Tipoti. Tyler knew immediately he had dislocated the shoulder, he said, but the team's training staff popped it back into place on the sidelines.
