Ronaldo has surgery on ankle

Manchester United forward Cristiano Ronaldo successfully underwent surgery on his right ankle in Amsterdam on Monday, the Premier League champions said on their Web site (www.manutd.com).

Ronaldo said after Portugal's Euro 2008 exit that he had been carrying an ankle injury for several months and it now appears certain he will miss the start of the new season.

United said in a statement that it would be one month before they could offer a time frame for Ronaldo's return.

"Initial indications are that the procedure was successful," United said.

"Cristiano will begin his convalescence under the direction of club medical staff and an estimation of his return to full fitness will be possible following a review by the specialist in one month."

Ronaldo has said that he is considering his future, with Spanish champions Real Madrid making little secret of their admiration for the 23-year-old. United have said he is not for the sale.