Ronaldo reported the injury in the aftermath of Portugal's Euro 2008 exit and suggested he would fly back to Manchester for an operation.

But the 23-year-old did not return as United medical staff felt a period of rest, which Ronaldo was due anyway, was a better course of action.

However, Ronaldo has since met with medical staff from both Portugal and the Red Devils, with further information now being sought.

impressive appearance

"Manchester United medical staff met with the medical team from the Portuguese FA and Cristiano Ronaldo in Lisbon today regarding the ongoing treatment of his injured right ankle," said a statement released by United on Wednesday evening.

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

Although Sir Alex Ferguson's squad began training on Wednesday, Ronaldo is not due back in England for another fortnight.

The player has an impressive appearance record since his move from Sporting Lisbon in 2003, since when he has rarely been injured.