Spencer Sanders sustained a high right ankle sprain in the first quarter and did not return for Oklahoma State during the Cowboys' 16-7 season-opening win against Tulsa on Saturday .The redshirt sophomore quarterback suffered the injury on the Cowboys' opening drive when he went 2-for-2 for 23 yards before Alex Hale hit a 27-yard field goal to go up 3-0. Sanders was hit awkwardly twice on the drive, once on a run when he was tripped up and another while scrambling to his left.Sanders limped to OSU's locker room without assistance and junior college transfer Ethan Bullock replaced him on the next drive. "He doesn't have a serious injury," OSU coach Mike Gundy said of Sanders. "I haven't visited with anybody medically other than them telling me during the game that he wouldn't be back today , so I really don't have information on him."Bullock was 8 of 13 for 41 yards, but threw one interception and had trouble moving the ball . Trailing 7-3 late in the third quarter, true freshman Shane Illingworth replaced Bullock. Illingworth completed 4 of 5 passes for 74 yards in his debut.