Oklahoma quarterback Trevor Knight has not been cleared medically for Saturday's game against Texas Tech, the Sooners announced on Thursday.
Over nine games this season, Knight has passed for 2,197 yards with 14 touchdowns and nine interceptions. The sophomore was once considered in the running for the Heisman Trophy, but his candidacy has lost steam.
Thomas has thrown for 50 yards with an interception and zero touchdowns in four appearances this season.
The Baylor loss caused Oklahoma (6-3, 3-3 Big 12) to drop out of the latest version of the College Football Playoff rankings. After the Texas Tech game, the Sooners host Kansas and Oklahoma State to close the regular season.