The newly-appointed Chelsea manager, who officially takes over at Stamford Bridge following the conclusion of Euro 2008, knows the talented winger well from their time together in the Portuguese national team, where Scolari will step down as manager on July 1.

Ronaldo led the Red Devils' charge to a Premier League and Champions League double last season, peaking the interest of Madrid, who now look to land the superstar for a record transfer fee.

However, United insist their player is not for sale and will not be listening to any offers, but Scolari believes that once Ronaldo has made up his mind, he will not be persuaded to change it.

He said: "I know Cristiano well and I know the type of person he is so I have no doubts about how he will handle himself in the next few weeks.

"People must understand that Cristiano becomes stronger with all the difficulties and the stories about him. I have never known anyone so mentally strong.

"He is so strong mentally and he is in control of his own destiny - and because of that Manchester United can do nothing to hurt him.

"It is his dream to play for Real Madrid and I am sure Cristiano will fulfil his dream whatever the difficulties."