ARLINGTON, Texas -- Baylor starting quarterback Charlie Brewer left the Big 12 championship game against the Oklahoma Sooners in the first half Saturday and will not return, coach Matt Rhule said.

Brewer's helmet hit the turf on a sack by Oklahoma's Kenneth Murray early in the second quarter, and he was slow to get up.

"He's out," Rhule told ESPN's Holly Rowe at halftime. "They're going to evaluate him and err on the side of caution, so he'll be out for the rest of the game."

After the play, Brewer was briefly evaluated by the Baylor training staff, but he returned for another offensive series. After that possession, head referee Mike Defee asked Rhule to have his training staff again examine Brewer, according to Rowe.

After the second sideline examination, Baylor sent Brewer to the locker room for further evaluation.

Redshirt freshman Gerry Bohanon entered the game in place of Brewer and led the Bears to their first touchdown drive of the day on a 33-yard pass to Tyquan Thornton.

Prior to Saturday, Bohanon, the No. 130 overall prospect in the 2018 ESPN 300, had made 10 career appearances, including eight this season, and had 257 career rushing yards and 131 passing yards. He relieved an injured Brewer and finished the Bears' win over Kansas State on Oct. 5, but he only attempted eight passes in the final eight regular-season games.

Brewer was 3-of-6 for 15 yards prior to leaving Saturday's game against the Sooners. He started every game for the No. 7 Bears this season, ranking second in the Big 12 in passing efficiency and fifth in touchdown passes (20) and passing yards per game (244.6).