Cameroon captain Samuel Eto'o has been ruled out of action for the next 10 days -- meaning he may play no further part in the World Cup.
Eto'o will miss Cameroon's final two group games, against Croatia and hosts Brazil, because of a knee injury, officials have confirmed.
"Eto'o has been told by the doctors he cannot play for the next 10 days," the team's media spokesman, Laurence Fotso, said.
On Monday, Eto'o confirmed on his Twitter account that the knee problem meant he would definitely sit out the Croatia game.
The four-times African Footballer of the Year wrote: "The doctors confirm! I would probably not be able to play the match vs Croatia... due to an injury on my knee causing me pain."
The doctors confirm! I would probably not be able to play the match vs Croatia on Wed, june18th due to an injury on my knee causing me pain.- Samuel Eto'o (@setoo9) June 15, 2014
Chelsea striker Eto'o has been struggling with a knee problem since the end of the Premier League season.
He told Cameroon state television on Sunday: "During the match [a 1-0 defeat] against Mexico I tried -- but after consulting the medical staff we realised that I needed a rest. Even in the ninth minute, I felt pain.
"For three-and-a-half months, I have not had the time to recover. You could see that even in the buildup to the World Cup I hadn't had a lot of practice until the friendly against Germany."