Former Manchester United football star George Best remains in intensive care after being hit with a new infection.
George Best is back in intensive care
The 59-year-old is on dialysis with a "severe infection", his doctor Professor Roger Williams said.
Former team-mate Denis Law, after a hospital visit on Friday, said: "He is a fighter but you just feel it is not good. He was more or less unconscious."
Best, who had a liver transplant in 2002, had previously shown signs of recovery after weeks of illness.
Mr Williams, speaking outside the Cromwell Hospital in London, said on Friday: "Mr Best is not so well. He has been admitted back to intensive care. He has got a new and severe infection.
"He was maintaining some progress each day and now he was acquired another infection as these patients are very susceptible to infection at this stage of recovery."
Mr Williams said the medical team had been very disturbed at this "sudden setback" after the steady progress he had made over the past two weeks.
The professor said he was hoping the infection would respond to antibiotics, however, he added that medical staff were not sure exactly where the infection was.
Last month, the former Northern Ireland international was taken back into hospital with a chest infection and internal bleeding.
In late October, however, he rallied and was reported to be able to leave his bed for short periods.
At that time, Professor Williams, said the infection was not directly related to his problems with alcohol.
But he said he would have been more susceptible to the illness due to medication to suppress the immune system and prevent his body rejecting a new liver.
Best, who was born in east Belfast, was arguably the most naturally gifted British footballer of his generation.
He made his professional debut for Manchester United in 1963, aged 17, and helped the club become the first English side to lift the European Cup in 1968.
Best was voted both English and European Footballer of the Year that season and also won 37 international caps.