Article Photos: Oklahoma football: Sooners' Charles Tapper says defense has plenty of room for improvement 43/99

Oklahoma's Charles Tapper (91) and Corey Nelson (7) bring down Tulsa 's Cody Green (7) during the college football game between the University of Oklahoma Sooners (OU) and the University of Tulsa Hurricanes (TU) at the Gaylord-Family Oklahoma Memorial Stadium on Saturday, Sept. 14, 2013 in Norman, Okla.  Photo by Chris Landsberger, The Oklahoman