Ivory Coast defender Kolo Toure has malaria, the country's football federation has announced. He has suffered from the disease before, in 2008.
The 33-year-old defender fell ill on a trip home to Abidjan before joining the team's World Cup training camp in Dallas, the team's doctor said.
Cyrille Dah told the Ivorian Football Federation website, www.fif-ci.com: "Since Wednesday Kolo has been having treatment. This treatment will end on Friday. We have therefore told him to rest. He will not participate in the match against Bosnia-Herzegovina (on Saturday), but will return early next week."
Toure was a bit-part player for his club Liverpool last season, but has won more than 100 caps for this country.
Ivory Coast kick off their World Cup campaign against Japan in Recife on June 14. Colombia and Greece are their other opponents in Group C.