Ronaldo has a Man United minder watching him in LA

Sir Alex Ferguson says he is taking no chances with Cristiano Ronaldo. He has a minder tracking the injured Manchester United star.

The 23-year-old has been sidelined for three months by an ankle operation following a summer spent being pursued by Real Madrid and has been allowed to spend the last 10 days in Los Angeles after securing a new commercial deal.

But Ferguson says he is unconcerned about reports and photos of Ronaldo hitting the Hollywood nightclubs - because United have employed their own security specialist to protect the £70millionrated Portuguese winger.

Ferguson said: "We have someone with Cristiano at the moment so we know exactly what is happening out in Los Angeles.

"We also know that a lot of the things that have been said about him while he's out there are a load of rubbish.

"There was one report that he had been drinking vodka. I immediately spoke to the person we've got with him and he told me, 'It isn't true boss, he isn't drinking'. So when I see things like that I know it is a load of rubbish.

"When Cristiano comes back to us in 10 days and removes the strapping and protective boot, he can start work on his recovery."

Ferguson also dismissed suggestions that Ronaldo's career is beginning to mirror that of David Beckham.

Beckham was ruthlessly sold to Real Madrid when the United boss decided that his showbiz lifestyle had taken away his edge.

And there have been tales from Sunset Strip of Ronaldo partying with a string of beauties which have included good-time hotel heiress Paris Hilton.

It is ironic that Beckham is now winding down his career in LA, but Ferguson said: "I am not getting into comparisons, but it is obvious that they are different.

"Any young player is going to get attention. The important thing is how they handle it.

"We know that success changes people, but often that means an elevation in their own esteem and personality and that can make them better players. Cristiano is now reaching the stage of his career when he will stamp his presence and personality on the world stage - and we have a duty to help him.

"That's why he was always scheduled to have this time in Los Angeles. There was never going to be any harm in him going there."

Ferguson believes that Ronaldo has a key role to play in a team with the potential to become United's greatest ever. But he insists that the quest to emulate Liverpool's Bob Paisley - still the only manager to lift the European Cup three times - is a peripheral concern.

Ferguson said: "After winning the title and the Champions League last season it was clear to me what I had to say to the players when we started pre-season. I asked them whether they wanted it all again.

"Certainly, if this team can win the Champions League again it will put them on a different platform to any other team in United's history because it hasn't been done before.

"The bottom line is that we have still only won three European Cups and we want to close the gap on clubs like AC Milan, Liverpool, Bayern Munich and Ajax.

"If the Munich disaster hadn't happened then maybe we would already be in the same frame as those clubs, or even have eclipsed them.

"I didn't know that Bob Paisley is the only manager to have won it three times. But, to be honest, that doesn't matter to me because it isn't about me."