Former Scotland, Manchester United and Leeds defender Gordon McQueen has been diagnosed with vascular dementia.
News of the football legend’s illness was shared by his family, who said he now wanted current players to "know there may be risks with persistent heading of the ball".
A statement released by his wife Yvonne, daughters Hayley and Anna, and son Edward read: "In January, Gordon McQueen, our dad was formally diagnosed with vascular dementia.
"As a family we felt it was important to let people know, particularly if raising awareness can help others in similar situations.
"Whilst as a family we’ve found it hard to come to terms with the changes in dad, he has no regrets about his career and has lived life to the full.
"But he wants other footballers of today’s generation to know there may be risks with persistent heading of the ball.
"Dad scored some important goals in his career and memorable headers but used to stay back in training, heading the ball to the goalkeeper for practice over and over.
"He does wonder if this has been a factor in his dementia as his symptoms appeared in his mid-60s."
McQueen’s daughter Hayley later posted on Twitter: "Heartbreaking not to be spending precious time with dad of late but trying to stay positive & also raise awareness about vascular dementia as a family.
"It’s a cruel disease but had plenty help recently from both @PFA and @FA. Thank you for the messages of support on here already."
The brothers’ 1966 World Cup-winning team-mate Nobby Stiles also died with dementia last year.
The Football Association (FA) is currently supporting two independently led research studies examining former professional players for early signs of neurocognitive degeneration.
The FOCUS study by the University of Nottingham is being funded by the FA and Professional Footballers’ Association, while the HEADING study by the London School of Hygiene & Tropical Medicine is being funded by the Drake Foundation.
McQueen, 68, started his career at St Mirren before moving to Elland Road in 1972, winning the First Division two years later and playing an important role in their run to the 1975 European Cup final.
He went onto enjoy a successful time with Manchester United and represented Scotland on 30 occasions, scoring five goals.
Having managed Airdrie during a coaching career that included time at Middlesbrough, the ex-centre-back went on to become a popular TV pundit with Sky Sports.
© Sky News 2021