The legendary ex-England international is a great admirer of the Everton boss and thinks he has similar qualities to those of the United chief.
"You can never say how much we should appreciate Alex Ferguson because he's been just brilliant," Sir Bobby told MUTV. "He'll be there forever in football history. Marvellous.
"But David Moyes is, I think, a very capable person. He's got a great knowledge of the game and is steeped in the game, very much like Alex, although they're all different. When he comes here, I believe he will think he's in paradise as he's got so many good players and good coaches.
"When Alex decided he'd maybe had enough, I didn't know what to do really but he's just a wonderful person and it [the success] will continue because people have learned a lot from him."