Former Wales defender Keith Pontin died from dementia caused by repeated trauma to the head during his playing career, an inquest found on Tuesday.
Pontin played for Cardiff, who currently play in the second tier of the English game, between 1976 and 1983 and was capped twice by Wales.
He was diagnosed with early onset dementia in 2015 aged 59, and died in August 2020 aged 64.
Pontypridd Coroner's Court in Wales heard that a post-mortem examination carried out on Pontin found the cause of death to be chronic traumatic encephalopathy (CTE).
Glasgow consultant neuropathologist Willie Stewart, who examined Pontin's brain tissue, said: "The overwhelming pathology was of chronic traumatic encephalopathy."
CTE is a progressive brain condition believed to be caused by repeated blows to the head and episodes of concussion. The symptoms of CTE affect the functioning of the brain and eventually lead to dementia.
Stewart's previous research showed ex-professional footballers were 3.5 times more likely to die from neurodegenerative diseases than the general population.
During the hearing, a list of the injuries Pontin suffered throughout his career was read to the court, including a concussion when he was 18.
There are growing concerns over the link between various sports and long-term brain injury.
Stewart said there was "no evidence yet suggesting changes in the modern game have altered the risk".
The coroner, David Regan, said he found Stewart "extremely persuasive" and concluded: "Keith Pontin died from chronic traumatic encephalopathy caused by repetitive head injury suffered as a professional footballer."
Several members of the 1966 England World Cup-winning squad, including Jack Charlton and Nobby Stiles, were suffering from dementia at the time of their deaths.