Oklahoma quarterback Baker Mayfield's status is uncertain for Saturday's showdown with Oklahoma State.
Mayfield was injured during Saturday's 30-29 win over TCU. He was shaken up early in the second quarter by a helmet-to-helmet hit from TCU linebacker Ty Summers, who was ejected for targeting.
The fifth-ranked Sooners (10-1, 7-1 Big 12) can clinch the conference title with a victory over the ninth-ranked Cowboys (10-1, 7-1). Oklahoma coach Bob Stoops said Mayfield will be evaluated by medical staff before any decisions are made.
''That'll all be up to our doctors and trainers,'' Stoops said after the game. ''It's a short time after the game. I sure don't know anything right now. They'll be thorough, though, in checking him, and do what they need to do.''
Mayfield rose on Heisman Trophy watch lists after leading the Sooners to victory at Baylor the previous week. He's completed 69 percent of his passes, with 32 touchdowns and five interceptions. He also 343 yards rushing and six TDs.
Mayfield played the rest of the first half after the hit from Summers.
''Our trainers and doctors were constantly, with each series, every time Baker was off, checking him, asking him questions, making sure he was OK, and everything was checking out fine,'' Stoops said. ''And then at halftime, they approached him again to go over some things and Baker admitted to having a headache, and that's when our doctors said we're not going to have him play.''
Trevor Knight stepped in and completed just 5 of 16 passes for 76 yards, with one interception. Offensive coordinator Lincoln Riley took the blame for Knight's struggles.
''We weren't aggressive enough,'' Riley said. ''We got away from who we are offensively. That's my fault. That can't happen.''
Knight would start Saturday if Mayfield can't go. He led the Sooners to a Sugar Bowl win after the 2013 season and was the starter last season. He lost the starting job to Mayfield in preseason practice. Riley said he's confident Knight would be ready next week if called upon.
''There's not anything in this offense he can't do,'' Riley said. ''This is a guy that came as close as it could be to starting the season as a starter and a guy that's won a lot of games, a lot of major games.''
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