Ferguson told The Sun: “How players manage to handle that celeb-kind of attention we will never know.
“But with Ronaldo he seems to do OK. He seems to be fine and does not seem to be overwhelmed or overly flattered by it.
“The problem comes when players get flattered by it and start to enjoy it, that is when you start worrying.
“At 22 there is no sign that the boy will be wasted by it.”
Ferguson added: “It is obvious when a talent like Ronaldo comes along that there will be attention. This club has been used to that for years now.
“This club is great at creating heroes no question about that. At his age you have to be flexible when it comes to curtailing their youthfulness.
“I remember Ryan Giggs coming into training once wearing a certain new jacket and I said to him ‘where the hell did you get that?’
“But he was a young lad and young people do these kind of things. They like to dress differently and they want a bit of freedom with their choices. They want to be men before they are men.
“With Cristiano, a lot has happened to him in his time at Manchester United. But he is an intelligent boy and looks after himself. He has matured fantastically well. He has a lot of plusses.
“Last season there was a tremendous improvement in the boy in terms of his goalscoring.
“To get 23 goals for a wide player today is incredible, there are not many players who can do that.”
