Oklahoma quarterback Trevor Knight will miss Saturday's game at Texas Tech.
Coach Bob Stoops made the announcement Thursday via the football team's Twitter account.
Knight was injured while being sacked during the fourth quarter of last Saturday's 48-14 loss to Baylor. Stoops said Monday that MRIs and x-rays were negative, and it wasn't a concussion or head injury, but he never specified what the injury was.
Knight has an 11-3 record as Oklahoma's starter, and he was the MVP of the Sugar Bowl last season after passing for 348 yards and four touchdowns. He has been erratic this season.
Freshman Cody Thomas will get his first career start. He has thrown just 16 passes at Oklahoma, but he stepped in and led a touchdown drive against Kansas State.