Muschamp announced the departures in a concise statement Saturday saying the two were "no longer part of the team."
Harris, a 5-foot-11, 154-pound junior, is the son of former NFL standout Al Harris. The younger Harris was voted by SEC head coaches to its all-freshman team in 2014. He made 25 tackles in 11 games this past season. Harris had nine starts in the secondary this past fall.
Johnson is a 6-1, 250-pound junior who had 20 tackles last season, as he started three games.
Muschamp took over as head coach in December.