ARLINGTON, Texas — First, Oklahoma lost its Heisman quarterback. Then, the Sooners lost the game. With Sam Bradford only able to watch from the sidelines, Brigham Young rallied for a 14-13 victory Saturday night at Cowboys Stadium to stun the third-ranked Sooners in the season opener. Bradford suffered a sprain to the acromioclavicular joint in his throwing shoulder late in the second quarter. X-rays were negative, but Bradford could be out weeks, depending on the severity of the sprain. Coach Bob Stoops claimed after the loss he wouldn’t know until today or Monday how long Bradford would be out. "I think until they can get home and MRI it and get more reviews of it, I don’t think we’ll know,” Stoops said. Bradford watched the second half from the sidelines with an icepack on his shoulder and his arm in a sling. Redshirt freshman Landry Jones replaced Bradford in the second half, but the Sooner offense sputtered without Bradford or All-American tight Jermaine Gresham, who missed the game due to cartilage damage in his knee. Bradford’s injury came on a rollout pass in the first half. After Bradford released the ball, BYU linebacker Coleby Clawson drove Bradford’s shoulder into the turf. Bradford lay on his back and clutched his injured shoulder until the training staff helped him off the field. Walking to the locker room, he was unable to lift the arm from his side. In place of Bradford, Jones completed 6 of 12 passes for 51 yards with no interceptions, but penalties by the offensive line kept the Sooners from sustaining any offensive momentum. After BYU scored a touchdown to go ahead with 3 minutes left, Jones drove the Sooners into Cougars’ territory to set up a 54-yard game-winning field-goal attempt by Tress Way. But Way’s try fell short, and BYU ran out the clock to come away with the win.