Crerand said: "Welcome to United, what a start that is.
"It really is a great first home game having Mourinho coming and it could really give David some great momentum to win that.
"If he can be top of the league after those first five games it'll be a marvellous start for him.
"Liverpool away is never easy in a one-off although I don't see them being rivals for the title.
"Then City away is obviously going to be tough. They already had a very good squad but have been adding to it already this summer.
"I can't quite understand the change of manager, I find it an amazing situation, so it will be interesting to see how the new boss adapts."