Starting center Gabe Ikard was ruled out of No. 14 Oklahoma's game against Baylor on Saturday after doctors did not clear him to play following a head injury.
Team spokesman Pete Moris said just before kickoff that Ikard would not play.
Ikard had started every game at center for the Sooners, filling in after entrenched starter Ben Habern gave up football at the start of training camp because of lingering medical issues.
Freshman Ty Darlington started in place of Ikard. Tackle Lane Johnson, who has been dealing with an ankle injury, also did not start.