David Moyes, who takes over as United boss on 1 July, said: "I would like to put on record the club's thanks for everything Mike and Eric have done. I will be looking to appoint my own members of coaching staff at some point in the future, however, I’d like to take this opportunity to give them both our best wishes for their future careers."
Executive Vice Chairman Ed Woodward said: "I'd like to thank Eric and Mick for the enormous contributions they have made to the success of Manchester United in their time here. Their professionalism, ability and diligence have been a credit to them. They are top class football men and everyone here wishes them well for long and successful careers in the game."
Mike Phelan, a former United player, was promoted by Sir Alex Ferguson to the role of assistant manager in 2008, having served the club as a first-team coach since 2001.
Eric Steele, joined the club in 2008 as first-team goalkeeping coach to fill the void left by Tony Coton who had been forced to retire due to injury.