Euro star: Cristiano Ronaldo with the European Cup

Cristiano Ronaldo will undergo an operation on his troublesome right ankle within the next two to three days, according to Portugal medical staff.

The Portugal superstar's club Manchester United have, however, denied that any such decision has been made.

Ronaldo, whose United future is in doubt with Real Madrid desperate to secure his services for a world record fee, met medical staff in Lisbon yesterday to have the damaged ankle assessed.

United club doctor Steve McNally, along with the Portugal national team doctor, held a consultation with Ronaldo in the capital, at which it was decided the winger should undergo surgery.

The Portuguese contingent have since come out and revealed that the twice Player of the Year will go under the knife.

Ronaldo has been suffering with the injury since April, but played through the pain barrier on his way to helping United secure a second straight Barclays Premier League title as well as the Champions League crown.

The imminent operation and estimated four-week recovery period means Ronaldo will not return to pre-season training with United on July 14, the date he was due back.

Pain game: Portugal's Cristiano Ronaldo grimaces in pain during the Euro 2008 quarter-final between Portugal and Germany

Although it is still unclear whether he will be playing for United or Real next season, Ronaldo's camp are confident he will be fit for the beginning of the new season.

If anything, the operation and Ronaldo's recuperation in his homeland is likely to work to Real's advantage, with the winger away from United and any influence upon him to stay in Manchester.

United are, however, insisting no decision has yet been made as to whether Ronaldo will need surgery on his right ankle.  

But United, who issued a statement last night about Ronaldo's injury, are baffled by those comments.  

Sir Alex Ferguson: has yet to speak to his errant winger Ronaldo

A club spokesman reiterated: 'Procedures are in place to seek specialist advice, in order to finalise the treatment plan as soon as possible.' 

Last night they had stated: 'Manchester United medical staff met with the medical team from the Portuguese FA and Cristiano Ronaldo in Lisbon today (Wednesday) regarding the ongoing treatment of his injured right ankle.  

'As a result, further specialist advice is being sought and an announcement will be made on any action in due course.'

Should it be decided an operation is required, it could have a major impact over the Madeira-born winger's fitness for the start of the new season.

That in turn may determine how far Real Madrid are willing to push their attempts to lure him away from Old Trafford.

Ronaldo is not due back in England for another fortnight and manager Sir Alex Ferguson is yet to speak to him about the large number of statements from Madrid - which went unchecked by the player - during Euro 2008.

Eventually, United grew so sick of Real's advances that they reported the matter to FIFA, although the world governing body subsequently rejected it.

Ronaldo refused to comment on his future when he returned to Portugal after a break in Italy.

'I can only say that I will spend the period of my recovery in my house in Sintra, but regarding my future I cannot say anything,' Ronaldo said in Portuguese newspaper A Bola.