Suspended FIFA president Sepp Blatter is under "medical evaluation" for stress, according to his spokesman.
The 79-year-old, who is currently serving a 90-day suspension from all football-related activity, has been ordered by doctors to rest at his home in Switzerland.
Blatter's spokesman Klaus Stohlker is quoted by BBC Sport as saying: "He is under medical evaluation. The doctors took him out for a few days. The doctors expect to him be back around Thursday or Friday of next week.
"He is under tremendous pressure from so many sides and perhaps this is a little bit difficult for a man who is not the youngest."
Blatter is being investigated by the authorities in relation to an alleged "disloyal" payment of £1.3m made to UEFA president Michel Platini in 2011.
The allegation is the latest in a string of corruption accusations surrounding football's world governing body FIFA.
Switzerland's Radio 1 reported today that Blatter had suffered a "medical incident" earlier this week.