Quarterback Baker Mayfield suffered a head injury during the second quarter of No. 7 Oklahoma's30-29 win Saturday over No. 18 TCU, leaving his status for the Sooners' regular-season finale atOklahoma Statenext weekend unclear. The Heisman Trophy hopeful took a shot in the back of the helmet from TCU linebacker Ty Summers, who was ejected for targeting. Mayfield stay in the game for the rest of the first half, but was pulled and replaced with Trevor Knight after admitting to doctors during halftime that he had a headache. Oklahoma coach Bob Stoops said he didn't immediately know if Mayfield would be available to play at Oklahoma State, which lost its first game of the season Saturday toBaylor. The Sooners can clinch the Big 12 title with a victory in Stillwater.