Oklahoma football: Johnny Manziel will be OU's greatest challenge from an individual this season - Article Photos 1/2

Texas A&M's Johnny Manziel (2) reacts after a touchdown run during the second quarter of an NCAA college football game against Florida in College Station, Texas. Manziel could become the first freshman to win the Heisman Trophy when the award is presented Saturday, Dec. 8, 2012, in New York. (AP Photo/Dave Einsel, File)