The Confederation of African Football insists that acting Fifa president Issa Hayatou is fit to fulfil his duties, despite long-running health problems.
The Cameroonian, who arrives in Zurich to take control of football's world governing body on Tuesday, has kidney problems that require regular dialysis.
"Since his first election as Caf President, Hayatou has always assumed, without interruption, the powers vested in him," said the Caf statement.
"It has never been a secret that in recent years, kidney-related problems has seen him undergo regular dialysis sessions.
"The programming has always been done in harmony, with the agenda and multiple professional obligations honoured smoothly."
As the longest-serving vice-president of football's world governing body, Hayatou, 69, has assumed the acting president role following the 90-day suspension handed out to Sepp Blatter.
The 79-year-old was suspended by Fifa's Ethics Committee on Thursday as it investigates corruption claims against him.
On Friday, it was announced that Blatter has appealed the decision.
President of African football's ruling body since 1988, Hayatou will arrive at Fifa's headquarters early next week following official Caf business in Equatorial Guinea over the weekend.
He is 'in perfect control of his physical potential and rightly strong', says Caf.
The statement went on to list the presence of Hayatou at various official functions to emphasise their point - mentioning ten countries he has visited this year.
The long-standing Caf president has already stood in for Blatter this year, handing over the Women's World Cup trophy in Canada to the winning United States side in July.
It was the first time Blatter had failed to present the trophy since he became Fifa president, with his lawyer explaining his absence on 'personal reasons'.
The move came amidst the heightening crisis that has gripped Fifa since May, when the United States indicted 14 officials on charges of bribery, racketeering and money-laundering, involving tens of millions of dollars since 1991.