Houston quarterback Case Keenum was injured Saturday night while trying to make a tackle for the second straight week.
UCLA linebacker Akeem Ayers intercepted Keenum's pass near the goal line late in the second quarter, and Keenum was left facedown on the turf after attempting to tackle Ayers during a 77-yard return.
Keenum incurred a concussion last week while trying to make a tackle after an interception by UTEP's Travaun Nixon, and the 23rd-ranked Cougars didn't confirm he would play against UCLA until he took the field with the offense.
Keenum stayed down on the Rose Bowl grass for two minutes before walking gingerly to the Houston sideline, where team doctors stretched him out on a table before putting him on a golf cart and taking him to the locker room.
Backup quarterback Cotton Turner replaced Keenum with the Cougars' offense when UCLA's Malcolm Jones fumbled on the next play.
Keenum was 10 of 18 for 83 yards against the Bruins, but threw two interceptions deep in UCLA territory.
Houston trailed UCLA 21-3 at halftime.
Keenum is the fifth-leading passer in NCAA history after becoming just the second quarterback to pass for 5,000 yards in two different seasons. He led the nation in total offense and passing offense last year, his second straight season leading the Football Bowl Subdivision in total offense.