Texas Tech quarterback Will Hammond tore the ACL in his right knee and will miss the rest of the season, sources told ESPN's Pete Thamel on Sunday.
The redshirt freshman backup hurt the knee in the second quarter of the Red Raiders' 42-0 win over Oklahoma State on Saturday and didn't return to the game. Hammond was making his second consecutive start in place of injured starter Behren Morton.
Third-string quarterback Mitch Griffis replaced Hammond to finish the game for the No. 14 Red Raiders. The senior transfer threw for 172 yards on 9-of-13 passing and had two total touchdowns in the program's first shutout win over a Big 12 opponent since 2005.
Morton continues to recover from a right leg injury and was considered available for the game in case of emergency. He was in uniform at halftime in the event he needed to play against the Cowboys.
ESPN's Max Olson contributed to this report.