Tanner Mordecai has replaced Spencer Rattler in the second quarter of Oklahoma's Red River rivalry game against Texas.
Rattler had just lost a fumble. It was his second turnover of the game and his sixth in the past three games.
Mordecai was 3-for-3 for 32 yards on his first drive, which ended when running back T.J. Pledger fumbled on the Texas 18.
Training staff was seen working on Rattler's arm on the sideline, but it's unclear whether the move was because he was injured.
Mordecai, a redshirt sophomore from Waco, Texas, was 14-of-17 for 157 yards with one touchdown and one interception coming into the game.