Former Scotland, Manchester United and Leeds United defender Gordon McQueen attributed his dementia to heading a ball, says his daughter.
McQueen, who was diagnosed with vascular dementia, died in 2023 aged 70.
An inquest into his death opened at the coroner's court in Northallerton, North Yorkshire, on Tuesday.
Asked whether she discussed with her father what was behind his dementia, daughter Hayley McQueen - a Sky Sports presenter - said: "He would say 'yes, heading a football all those years probably hasn't helped'.
"I remember coming home from school and Dad would be in bed. Or having a lie down.
"He would say he's been having headaches. I remember thinking 'why are you having headaches?'"
Centre-back McQueen made almost 350 appearances for St Mirren, Leeds and United between 1970 and 1985.
Hayley told the inquest she did not remember him having head injuries during his career, other than a few concussions.
She described how his health deteriorated after the family noticed a change in his personality not long after his 60th birthday.
"He struggled with his swallowing and that continued for many years," Hayley said.
"His balance was very, very off and his personality started to change.
"My dad was very outgoing - dinners, part of the after-dinner circuit. He became off, which wasn't really my dad."
Hayley said the swallowing issue was dysphagia and that, although McQueen also had throat cancer, they learned more after a conversation between her mother Yvonne and Dawn Astle, the daughter of former England and West Brom striker Jeff Astle, who died in 2002 aged 59.
"He just wouldn't really know what year it was or what day it was," Hayley said.
"He was very active and trying to do crosswords and watch football. He lost the ability to write.
"He couldn't make a cup of tea. He got confused about what went where. He kept saying, 'there's something not right in my head'."
"He used to get confused about things. Never people - he had an incredible memory for the past.
"It was more the withdrawn nature of my dad. He would be the centre of attention, but (with dementia) he would have to be asked a question to speak."
Asked by Michael Rawlinson KC, representing the McQueen family, how her father scored his goals, Hayley said: "Mainly with his head, from a set-piece."
Professor Willie Stewart, a consultant at Queen Elizabeth University Hospital in Glasgow who examined McQueen's brain after his death, described how a membrane in the brain appeared torn and that chronic traumatic encephalopathy (CTE) was present in various places.
"Gordon technically fell into the lower stage of the disease, although on the threshold of the higher stage," he said.
Prof Stewart said symptoms of CTE were cognitive decline and neuro-behaviour change, and that they "can't be explained by another condition - it must be progressive".
He said symptoms were "typical in individuals who have long careers - professional footballers and rugby players".
Asked if there was a causal link between CTE and repetitive head injury, he said: "The answer to that is yes."
Senior coroner John Heath said the post-mortem found pneumonia in McQueen's right lung, mixed vascular dementia and CTE.
Prof Stewart, who conducted a 2021 study on whether certain positions on the pitch were more associated with neurodegenerative disease than others, said: "The players, the goalkeepers who don't head the ball had a risk equivalent to general population, whereas in outfield positions, particularly defenders, the risk was higher."
The inquest continues.
