Former England striker Frank Worthington has been diagnosed with Alzheimer's disease, his daughter says.
Worthington, 67, had a playing career spanning 26 years that included more than 200 appearances for Leicester.
He started his career at Huddersfield and also played for the likes of Leeds, Bolton Wanderers and Sunderland.
"He was diagnosed several years ago and has been holding it off with positive thinking and football," wrote Kim-Malou Worthington in a post on Facebook.
"They say several footballers from my dad's era seem to have suffered the same disease, possibly due to the constant heading of the heavy football back in the day."
Jeff Astle, another former England striker, died in 2002 from brain trauma which a coroner ruled was caused by heading heavy leather balls.
Three members of England's 1966 World Cup-winning squad - Martin Peters, Nobby Stiles and Ray Wilson - also have Alzheimer's, the most common cause of dementia.
The Football Association wants world governing body Fifa to investigate whether former players have dementia as a consequence of playing the game.
Worthington won eight England caps, scoring two goals.
He scored a memorable individual goal for Bolton during a Division One match against Ipswich in 1979.
Worthington went on to manage Tranmere Rovers in the mid-1980s and was player-coach at hometown club Halifax in the 1991-92 season.
His daughter added: "It's a funny thing that the one big lesson my dad always taught me was 'mind over matter'... no matter how hard life gets, being positive will pull you through, every adversity is an opportunity for change and growth.
"My heart goes out to all those affected by Alzheimer's, what a journey it is for all those affected."