Former England captain Dave Watson has a neurodegenerative disease which his wife Penny believes was most likely brought on by head injuries and repeated heading of the ball.
Watson, 73, won 65 caps and helped Sunderland win the 1973 FA Cup before guiding Manchester City to League Cup success three years later.
"Dave has good and bad days," she said.
"He tries to continue to enjoy a normal life, however almost every day we are confronted with a new challenge."
Penny Watson said her husband's consultant thought that it was "in all probability chronic traumatic encephalopathy (CTE)" - the disease determined as the cause of former West Brom striker Jeff Astle's death in 2002.
"If you come across him at a match or elsewhere, please don't be afraid to interact with him," she added - the former defender is set to be inducted into Sunderland's Hall of Fame next month.
"Please be considerate if he is having a bad day and struggling. This disease plays tricks on his memory, so he may not be able to remember accurately, and he may find signing autographs a challenge.
"The last thing Dave wants is to be treated with pity. He has always been a fighter, as those of you who watched him play know, but this is one battle Dave cannot win."
Watson played for Sunderland, Manchester City, Werder Bremen, Southampton and Stoke during his time as an England player.
Astle family campaign results in research
Following Astle's death, his family pushed for research into a possible link between heading footballs and dementia.
Neurosurgeon Dr Willie Stewart added the condition was frequently mistaken for dementia, as happened to Astle when he was incorrectly diagnosed with Alzheimer's.
In October, a study commissioned by the Football Association and the Professional Footballers' Association found that former footballers are approximately three and a half times more likely to die from neurodegenerative disease than the general population.
Football's governing bodies are now set to introduce new guidelines in youth football. The English FA suggests a restriction in the amount of heading by under-18 players in training, while the Scottish FA is set to ban under-12s heading the ball during training.
Fresh doubt has been cast over the future of Bury Football Club after they defaulted on a plan to help settle their outstanding debts.
Creditors approved a company voluntary arrangement (CVA) proposal last July which would have seen the club's football creditors paid in full.
Unsecured creditors, including HMRC, were due to be paid 25% of money owed.
Bury, who were expelled from the English Football League last August, had until Tuesday to pay the CVA.
"We will be looking at taking necessary action," said Steven Wiseglass of Inquesta Corporate Recovery & Insolvency. "No further comment can be made at this stage."
The club were deducted 12 points for the insolvency event but were eventually expelled from the EFL after a proposed takeover collapsed.
Bury, who had won automatic promotion from League Two just three months previously, were the first team to drop out of the EFL since Maidstone's liquidation in 1992.
Since their expulsion by the EFL the club, who were founded in 1885, have had two winding-up petitions over unpaid tax dismissed by the High Court.
The Shakers appeared to be on the brink of liquidation after a further prospective buyer ended their interest in October, but during a previous petition the club argued they had continued to automatically pay tax on wages that were not received by staff.
Businessman Robert Benwell addressed supporters in December about his plans to "bring football back to Bury", with one of the options being to start the club again if it goes into liquidation, but it is unclear what will happen to the club next and in what form.
How the club lost their place in the EFL
Dale bought Bury for £1 from previous owner Stewart Day in December 2018, but the Shakers were already in financial trouble by that point, with players and staff often being paid late.
A winding-up petition filed against the club was adjourned three times before eventually being dismissed by the High Court on 31 July.
Although the CVA had now been agreed, the EFL was not satisfied the club had given enough evidence of their financial viability, leading to a number of postponed fixtures while the organisation awaited "the clarity required".
On 9 August, the Shakers were given a 14-day deadline to provide the necessary information or face expulsion - and, although that deadline was extended, a final-hour takeover bid by C&N Sporting Risk collapsed.
BBC Radio Manchester's Mike Minay
It is still far from clear, at this point, what exactly will happen next for Bury and the CVA supervisor Steven Wiseglass.
The biggest concern for the Shakers will surround liquidation, which can come either through Steve Dale himself or Wiseglass - and could be triggered immediately.
If that were to happen, it is would likely to take up to six weeks to go through the courts. This would spell the end of Bury Football Club.
Equally, a creditor could take their unpaid debts through the court via a winding-up petition.
One final option - which isn't beyond the realms of possibility - is that a new CVA could be negotiated with new terms.
Administration is unlikely, although it does remain an option, but the club have little to trade at the moment with no playing staff and without a league to play in.
West Brom face Nottingham Forest in the Sky Bet Championship on Saturday, live on Sky Sports Football.
Sky Bet Championship leaders West Brom have no fresh injury concerns ahead of the visit of promotion-chasing Nottingham Forest. Veteran midfielder Gareth Barry (calf) has been stepping up his recovery, along with Chris Brunt and full-back Kieran Gibbs (hamstring) as they all close in on a first-team return.
On-loan West Ham midfielder Grady Diangana continues rehabilitation on his own hamstring problem but is expected to be back by the end of February.
Teenage defender Nathan Ferguson, who had been set to join Crystal Palace ahead of the transfer deadline, is sidelined following exploratory knee surgery. Nottingham Forest will hand Lewis Grabban a fitness test ahead of the trip to The Hawthorns, having missed the midweek home defeat by Charlton because of a knee problem.
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Midfielders Samba Sow and Sammy Ameobi also did not feature against the Addicks because of unspecified issues, but are expected to be available if needed. Manager Sabri Lamouchi reported no fresh injury concerns as Forest look to keep up the pace in the battle for automatic promotion.
Yuri Ribeiro and Matty Cash are set to be recalled to the starting 11.
West Brom have emerged from their winter slump with three wins in succession to move them six points clear of second-placed Leeds and put into the driving seat at the top of the Sky Bet Championship.
More on this story
Meanwhile, Forest have lost two of their last three league games this month. They lost 2-1 to Birmingham on February 1, before a significant 2-0 win over Leeds at the City Ground a week later. However, they couldn't follow that up with a victory over Charlton on Tuesday, when they lost 1-0 at The Valley.
2:01Highlights of the Sky Bet Championship match between Reading and West Brom.
1:48Highlights of the Sky Bet Championship match between Nottingham Forest and Charlton.
West Brom are winless in three home league games against Nottingham Forest (D1 L2) since a 1-0 win in November 2001.
Nottingham Forest have won none of their last three league games against West Brom (D2 L1), losing 2-1 on the opening day of this season.
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West Brom recorded their first home league clean sheet in their 2-0 win against Luton - the Baggies last kept consecutive home league clean sheets back in February 2017 under Tony Pulis in the Premier League.
Only Matt Phillips (5) has more Championship goals at the Hawthorns for West Brom this season than defender Semi Ajayi (4), who netted a brace in the 2-0 win over Luton.
Nottingham Forest winger Joe Lolley has been directly involved in seven goals in last 10 away starts in the Championship (3 goals, 4 assists).
West Brom are right back on it. Three wins on the spin, including in tough trips to Millwall and Reading, have sent them clear at the top. Sabri Lamouchi essentially sacrificed the game against Charlton to prepare for this, which means the pressure is on to get a win here.