Bowden says he made the decision Friday afternoon after watching tape of the Tigers 12-7 loss at Wake Forest the night before.
The Tigers play next at home against Georgia Tech on Oct. 18.
Bowden said he had to do something to spark the team, which is 3-3 with two conference losses. The coach said Korn is more mobile than Harper and gives the Tigers more options on offense.
Bowden stood behind offensive coordinator Rob Spence, despite the team scoring only one touchdown the past seven quarters.