Article Photos: Oklahoma coach Bob Stoops confirms Trevor Knight's knee injury; Blake Bell will start Saturday against Tulsa 48/61

Oklahoma's Brennan Clay (24) is brought down by Darwin Cook (25) and d'Vante Henry (18) during the second half of a college football game between the University of Oklahoma Sooners (OU) and the West Virginia University Mountaineers at Gaylord Family-Oklahoma Memorial Stadium in Norman, Okla., on Saturday, Sept. 7, 2013. Photo by Steve Sisney, The Oklahoman