The free agent reliever signed with the Sox in December of 2002 and was released on July 30, 2003. He blew a save in the 2003 opener in Tampa and went on to have a 4.50 ERA in 18 innings of work for the Red Sox. Fox was picked up by the Marlins, had a 2.13 ERA in 21 games, and went on to pitch in the 2003 World Series.