Detroit cut Henson on Wednesday, replacing him on the roster with Adam Jennings to bolster their special teams.
The Lions also released running back Allen Ervin from the practice squad.
Henson had been signed a month ago to be Detroit's No. 3 quarterback. He became expendable with the signing of Daunte Culpepper.
Henson threw one touchdown pass in seven games for the Dallas Cowboys in 2004. He skipped his senior season at Michigan to play baseball for the New York Yankees, but returned to football after three seasons.