Manchester United winger Cristiano Ronaldo was undergoing surgery Monday morning on his right ankle in Amsterdam.
The 23-year-old Portuguese revealed after last month's European Championship that he had been playing in pain for the last three months.
Ronaldo arrived at the Academic Medical Center on Sunday night to see surgeon Niek van Dijk.
"He was diagnosed yesterday evening and the surgery on his right ankle is this morning and is still going on now," hospital spokesman Johan Kortenray told The Associated Press.
Ronaldo scored 42 goals for the Red Devils last season as he powered them to them to triumphs in the Premier League and Champions League. But at Euro 2008 Portugal was ousted in the quarterfinals.