Manchester United and England legend Nobby Stiles has been described as "very, very poorly" by his son.
The 73-year-old, who played every minute of England's successful 1966 World Cup campaign, was diagnosed with prostate cancer four years ago and is also battling with advanced dementia.
Through his father's illness, John Stiles became involved with the Prostate Cancer UK charity and has urged men to get regular checkups.
"Like most of us, up to a couple of years ago I wasn't really aware how serious it was and how common it was," Stiles told the Manchester Evening News. "Like anybody when you hear that someone in your family has got cancer it's just like a knife going into your guts really, and coming to terms with it really.
"Lucky my father's been treated relatively successfully for it but when you hear the news it just knocks you sideways. He's very poorly. He has prostate cancer but he also has advanced dementia, early onset, like lots of footballers of his era.
"Like most people with advanced dementia he may be aware of it sometimes but it's just very, very difficult because he is very, very poorly. I look back and see my dad dancing about with the World Cup with sheer joy and it reminds you of a bygone era when players would actually play for nothing for their country. We are all very proud of my dad and all his friends, all his teammates."
During an 11-year stint at Old Trafford, Stiles made 311 appearances and scored 17 times, winning two league titles and a European Cup.