Henne began his Michigan football career starting at quarterback as a true freshman in 2004, the first Wolverine to do so since Rick Leach in 1975. Alongside freshman running back Mike Hart, he galvanized an explosive offensive unit that featured receivers Braylon Edwards, Jason Avant, and Steve Breaston. Henne's freshman season was highlighted by a triple-overtime win over rival Michigan State and a record-tying performance in the Rose Bowl against Texas. He also tied the Michigan season record for touchdown passes with 25, first set by Elvis Grbac in 1991.