NORMAN, Okla. -- Quarterback Baker Mayfield did not start the second half of Oklahoma's game with TCU after suffering an undisclosed injury.
The Heisman Trophy hopeful took a shot in the second quarter from TCU linebacker Ty Summers, who was ejected for targeting. Mayfield appeared shaken up after the hit but didn't immediately come out and even tossed a 36-yard touchdown pass to Dede Westbrook.
Mayfield was replaced by Trevor Knight, who was Oklahoma's first-team quarterback last season.
Mayfield completed 9 of 20 passes in the first half for 127 yards and two touchdowns.