Diego Maradona is to undergo emergency brain surgery to remove a blood clot, local media in Argentina have said.
Maradona was hospitalised on Monday for anemia and dehydration.
The 60-year-old has been undergoing tests and earlier on Tuesday his doctor Leopoldo Luque had said he was recovering well and his condition was improving.
Luque suggested Maradona, who won the World Cup with Argentina in 1986, could be released on Wednesday.
But Maradona is due to have an operation for subdural haematoma, a serious condition where blood collects between the skull and the surface of the brain often caused by a head injury.
Luque, Maradona's personal physician, said the procedure was a “routine surgery”.
“We are going to operate today,” said Luque on Tuesday. "He is lucid, he understands, he agrees with the intervention.
Maradona, the former Napoli, Barcelona and Boca Juniors player, is widely considered to be one of the greatest players of all time.
He is currently a coach at La Plata-based club Gimnasia in his native Argentina.
Dozens of the club's fans have converged on the hospital since Monday evening when he was admitted to the Ipensa clinic in La Plata.
