With less than three minutes to go in the game and USC driving inside Bruin territory Barkley's blindside came under attack as UCLA linebacker Anthony Barr delivered a blow Barkley wouldn't return from.
Barkley was replaced by freshman Max Wittek.
The senior quarterback laid on the ground for a couple of minutes being tended to by trainers before walking off the field on his own. After the game, he emerged from the locker room covered in a warm-up jacket, his right arm visibly not pulled through the sleeve, but appearing to be supported by a sling.
"We don't talk about injuries," Barkley said after the game.
He did however talk about his own performance, "I played up and down," he said. "I thought I fought as hard as I could have fought, went down fighting."
Opting to forego the NFL and return to Troy his senior season, Barkley admitted after the loss this is not how he expected the season to go, but he has no regrets. "There is nothing you can do now," he said, "why sit and pout about it."
Barkley finished the day completing 20-of-38 pass attempts for 301 yards, including two interceptions and three touchdowns.