Cameroon captain Samuel Eto'o is almost certain to miss Wednesday's World Cup game against Croatia because of injury.
Eto'o has not trained for two days and is unlikely to recover in time for the crucial Group A game in Manaus.
The 33-year-old striker wrote on Twitter: "The doctors confirm I will probably not be able to play because of a knee injury that is causing me pain."
Cameroon and Croatia both lost their opening games and are facing early elimination from the tournament.
Losing Eto'o would be a big blow for Cameroon, who were unable to impose themselves on Mexico and must improve significantly if they are to avoid an early exit.
Eto'o, who suffered a right knee injury at the end of his club season with Chelsea, told Cameroon Radio-Television (CRTV) he was hoping "the gods grant me a miracle and that I am able to defend my dear, beautiful country".
He added: "If this is not the case, I will always play my role as captain and especially as the big brother to push my young team-mates to victory.
"For three and a half months, I have not had the time to recover. You could see that even in the build-up to the World Cup I hadn't had a lot of practice until the friendly against Germany."
"During the match 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."