Sir Bobby Charlton has been diagnosed with dementia, his wife Lady Norma Charlton has confirmed to the Daily Telegraph.
Charlton is widely regarded as one of England's best ever players, having starred in the 1966 World Cup triumph.
Opinion: Solskjaer's Man Utd following same path as Lampard's Chelsea
He spent 17 years at Manchester United, becoming a first-team fixture after the Munich air disaster in 1958, which he survived.
Alongside his fellow so-called Busby Babes, he won two league titles in 1965 and 1967, in addition to the title before the plane crash in 1957.
In 1968, he scored twice in the final as United became the first English team to win the European Cup and he won the Ballon d'Or in 1966.
United confirmed the news, offering their condolences to the 83-year-old's family.
“Everyone at Manchester United is saddened that this terrible disease has afflicted Sir Bobby Charlton and we continue to offer our love and support to Sir Bobby and his family,” said the club in an official statement.
Shock suitors challenge PSG and Juve for Ramos signature - Euro Papers
Several other members of England's 1966 team have been diagnosed with dementia, including Charlton's brother Jack and his United team-mate Nobby Stiles, who both died this year.
Of the XI who faced West Germany in the 1966 final, only Bobby Charlton, George Cohen, Roger Hunt and Geoff Hurst are still alive.
'Clearly offside' - Solskjaer complains over Villa goal, Fernandes' missed penalty
Solskjaer tips Ronaldo to play on into his 40s