DALLAS -- Sam Bradford's college career at Oklahoma may be over after absorbing another jarring blow.
In a discouraging turn for the reigning Heisman Trophy winner, Bradford re-injured his right shoulder in the first quarter of No. 20 Oklahoma's 16-13 loss to No. 3 Texas on Saturday.
The junior was first hurt Sept. 5 against BYU when he sprained an AC joint in his throwing shoulder.
"It feels same way it did in BYU," said Bradford, who returned last week against Baylor after missing a month. "I really don't know the outlook from here. I'll talk to the doctors and find out what's wrong with it."
Bradford decided to pass on the NFL draft last spring in hopes of leading the Sooners to a national championship. Instead, Oklahoma's record-setting quarterback endured another mishap.
Unblocked Longhorns cornerback Aaron Williams jerked Bradford down while he was running backwards trying to get away from the defender on Oklahoma's second drive.
Williams got Bradford by the waist, but the quarterback landed on his shoulder and began writhing in pain right away. Landry Jones, who was 24 of 43 for 250 yards with a touchdown and two interceptions, replaced Bradford.
"It's extremely frustrating, obviously," Bradford said. "That's the way this season's gone for me. I missed three games, come out to start this one and hurt my shoulder. It's really hard to put into words the frustration I feel right now."
Bradford, who was 2 of 6 for 77 yards before leaving, tested his range of motion and tossed the ball on the sidelines. But it was clear he couldn't get any zip on it and was in pain.
Bradford tried holding his helmet with his right hand but it appeared to cause him discomfort and switched it to his left hand.
Soon, he was standing on the sideline without his helmet. Bradford would stand near the offensive huddle but would stay toward the back during timeouts. After the halftime, he had taken off his jersey and pads and stood on the sideline in a T-shirt.
Sooners offensive coordinator Kevin Wilson said he wasn't sure if Bradford would return this season.
"We'll exhaust every medical detail as far as MRI, timeline and what his best options are," Wilson said. "I think they did it the first time and everyone was comfortable with the way they went about it. Now he's had another setback. They'll relook and go from there."
Trips to the doctor and MRIs aren't Bradford had in mind when he put his NFL aspirations on hold.
In 2008, Bradford threw for a school-record 4,720 yards and led the nation with 50 touchdown passes. He would have been one of the top quarterbacks taken if he had left school.
"That's unfortunate," said Texas quarterback Colt McCoy, who became friends with Bradford on the college awards circuit. "I got to visit with him after the game. I told him I was praying for him and hoping he can get well."
Bradford threw for 389 yards in his comeback last week against Baylor. His 49 attempts matched second-most he'd thrown for in his career.
Sooners coach Bob Stoops said Bradford looked great in practice this week and dismissed suggestions that his star shouldn't have played.
"I saw him throw the prettiest 60-yard pass to finish our warmup as I've seen him throw," Stoops said. "We were going with information from doctors. He understood the entire situation. Sam is a bright, young guy. He knows what he wants. Unfortunately, it just hasn't worked out for him."