 After graduating from Broken Arrow Senior High, Dorsey began his college career as a defensive back at Ottawa, where, in 2003, he returned a kickoff 98 yards for a touchdown and was a second-team all-NAIA selection on defense.After his sophomore season, he transferred to Lindenwood.As a junior in 2004, he was named a first-team NAIA All-American as a defensive back after he scored three defensive touchdowns, even though he was moved from defense to running back with four games left during the regular season and rushed for 842 yards and nine touchdowns.