The 70-year-old, who has been in charge at Old Trafford since 1986, has not yet revealed when he plans to retire, but says Jose Mourinho could be the man to replace him.
"He can manage anywhere, absolutely," Ferguson told an ITV4 documentary. "I would never think a guy who hasn't played a game could be a top coach but then you've got to look at his personality. He's got a marvellous, strong personality and that bridges that gap.
"I remember his first press conference [at Chelsea] and I thought, 'Christ, he's a cocky b*****, him'. He was telling the players, 'Look, I'm the special one, we don't lose games'.
"Bloody hell, coming to England, he is only a young man and saying he is the special one! But it told all the players to have the belief they were going to win the League."
The Scot added that he enjoys a close friendship with the Portuguese, saying: "When he comes into my office he can take a joke against himself, that is what I like about him.
"I give him a lot of stick and he laughs it off. I don't think [his controversial image] bothers Jose. He knows it is results that count."