I am not sure about that. One thing about the midfield stars of the Ferguson era, were that they put in a serious shift, be it the central players, or the wide players. Keane, Ince, Beckham, Scholes, Fletcher, Park, Butt etc…. They all got about and had great engines.
I think the fact that he didn’t initially break in under Ferguson was probably more telling than people are willing to admit. This was from a manager notorious for promoting youth.
Either he didn’t like his attitude, or he didn’t think he had what it took to make it in a United midfield that was seriously lacking options at the time.