Luiz Felipe Scolari is looking forward to commencing battle with Sir Alex Ferguson tomorrow, and has talked in depth on his former Portugal man Cristiano Ronaldo.

Scolari worked with Ronaldo for a number of years in the international setup, and was with the winger during the summer, when speculation linked the 23-year-old with a move to Real Madrid.

Scolari believes that Ronaldo, who returned to the United side in midweek following a spell out with injury, is among the best players in the world.

'Now he is one of the three best players in the world. I don't say every time you are the best, but one of three, one of five or one of ten. Cristiano is one of the best in the world. There are maybe five or six others,' said the Brazilian.

'When I arrived in Portugal Ronaldo was a young boy, 17. In that time he had good character, and started as a very good professional, and thinking about his future. He improved himself very well in these five or six years.

'Now, maybe after this season and next season [he could be] a captain of Portugal because he has the confidence for this. People like him, and he can help the players. He has a good attitude on the pitch and outside. I don't know if the word is correct but he grows up, matures, and I think he is better than one or two years ago.'

As someone who has worked on the world stage for almost ten years, Scolari is well placed to nominate the pick of the talent. He explained that in his time as an international coach, each year he had to vote for his World Player of the Year.

'When I was coaching national teams I chose every year three players. In Brazil I don't remember but in Portugal one year I chose Didier, and now he is here. Another Terry and another Lampard, and now they are here and very good for me. Maybe next season Cristiano is with me - very well if he wants to change, I open the door!' he joked.

It certainly looked over the summer as though Ronaldo may be leaving Old Trafford, but he remains a Red Devil and will be keen to impress on his first league appearance of the season.

Having spent part of the summer together, Scolari added that they had not discussed the player's future on international duty.

'Maybe he'll play seven, eight more years in Manchester. Ronaldo is now 23, he has maybe 12 years until he is 35. He could play 12 years in Manchester, the manager reasoned.

'If he goes to other clubs in one year or two years I don't know. I am a friend for Cristiano, like a father. His life is his life, I said something once or twice when I was in the national team, but he has an agent, a mother, friends. He is an intelligent boy. In the summer I talked about Europe only.'

Someone else Scolari has talked with is Ronaldo's manager, and there lies within a great respect for Ferguson's work.

'When I saw Manchester United they were very organised, the players know what they do on the pitch. They recognise Alex as a very good coach and he gives them all the information.

'When I spoke to Cristiano Ronaldo about Alex, the players respect him as a coach, a father, a friend. He called for me in the national team at Portugal with this or that player and we had relations, and I met him two or three times because he is coach for a big team.

'We had a meeting in Uefa 15 days ago and had very good relations between the coaches, with Ferguson, Arsene [Wenger], the Sevilla coach (Manolo Jiminez), [Luciano] Spalletti and the coach for Bordeaux, Laurent Blanc.

'We had good relations but are opponents on the pitch, this is what the coach needs to think.'