The Browns waived safety Steve Cargile and signed defensive back Travis Key, the team announced Sunday.
Cleveland had claimed Cargile off waivers from Denver in early May.
Mitchell played in 45 games at Ohio State and ranked fourth on the team with 51 tackles and two interceptions as a senior.
Key is a former walk-on at Michigan State, where he had 113 tackles in 40 games. He started the 2007 season at strong safety for the Spartans.
Copyright 2008 by The Associated Press