Former England and Tottenham striker Jimmy Greaves is being treated in hospital for an unspecified illness.
The World Cup winner will have tests on Wednesday, according to his friend and agent Terry Baker, who added that the illness was "not coronavirus related".
The ex-Chelsea and West Ham forward suffered a severe stroke in 2015.
Baker also said the issue does not appear related to the 80-year-old's previous illness, adding: "Hopefully he won't be in hospital for too long."
On Tuesday, Spurs confirmed Greaves was having treatment in hospital.
"We are in touch with his family and will provide further updates in due course," the club said.
"Everybody at the club sends their best wishes to Jimmy and his family."
Greaves scored 44 goals in 57 games for his country and a club-record 220 league goals for Spurs.
He is fourth on the list of all-time England goalscorers, behind Wayne Rooney (53), Sir Bobby Charlton (49) and Gary Lineker (48).
Greaves was part of England's 1966 World Cup-winning squad but originally missed out on a medal because he was injured during the tournament's group stage.
After recovering, Greaves was left out of the starting XI for the final and his replacement, Sir Geoff Hurst, scored a hat-trick as England beat West Germany 4-2 after extra time.
The World Cup squad players and the families of manager Sir Alf Ramsey and other backroom staff were finally presented with medals in 2009.