United were crowned champions after beating Aston Villa 3-0 on April 22, but Hughes, who played for both the Blues and United in the 1990s, insists that it is not Ferguson's style to ease off.
"It will be a fascinating clash and I think United will just about shade it, [because] it is in the DNA of Sir Alex Ferguson not to lose," The Mirror quotes Hughes as saying.
"I played for him. I know what he is like. Yes, United have won the title and it is human nature that a little edge is taken off your game. But United won't be doing them any favours. Sir Alex doesn't believe in dead rubbers. He goes out to win every game — and this one is at Old Trafford.
"If United need an incentive, then it is that Chelsea put them out of the FA Cup. Chelsea needed a replay but they could easily have won in the first game at Old Trafford with their second-half performance."
Hughes has been out of work since being sacked as Queens Park Rangers boss in November.