He said: "My favourite for the Golden Boot is Ronaldo. (Klaas-Jan) Huntelaar has scored a lot of goals, but also has the handicap because the value of goals in Holland is different.
"For me, Ronaldo is above the rest and if he keeps scoring in this rhythm and stays in this sort of form then he will prove that he is the best.
"Ronaldo is better than George Best and Denis Law, who were two brilliant and great players in the history of United.
"But Ronaldo is 22 and with his quality and progression in the game, I believe he will be even better and win many more prizes for himself and his club.
"For him to be so good takes dedication.
But he also needs support from his team-mates and his coach, Sir Alex Ferguson.
"The only thing that I see as a weakness in his game is the number of assists, but he is young enough and has the right coach to improve in that respect.
"He scores great goals and now also spectacular free-kicks, but to be the complete forward he must provide more assists as his record can be improved."