Article Photos: Oklahoma football: Sooners' secondary shaky without Aaron Colvin, Gabe Lynn 34/99

Tulsa's Cody Green (7) is brought down by Oklahoma's Corey Nelson (7) as Frank Shannon (20) watches during a college football game between the University of Oklahoma Sooners (OU) and the Tulsa Golden Hurricane at Gaylord Family-Oklahoma Memorial Stadium in Norman, Okla., on Saturday, Sept. 14, 2013. Oklahoma won 51-20. Photo by Bryan Terry, The Oklahoman