Jeff Astle's daughter and widow have called for Professional Footballers' Association chief executive Gordon Taylor to quit after accusing the union of letting down the late West Brom and England striker.
Astle, scorer of West Brom's winner in the 1968 FA Cup final and a cult hero among Albion fans, died aged 59 in 2002 of chronic traumatic encephalopathy (CTE) linked to repeatedly heading heavy leather footballs.
His family have long campaigned to raise awareness around brain injury in football and they have become frustrated in their dealings with Taylor - who for his part insists the issue is "high on (the PFA's) agenda".
Astle's widow Laraine told the Daily Telegraph: "They have failed, swept it under a carpet. It is 15 years since Jeff died and we feel nothing has been done.
"Gordon Taylor has waffled his way through. They should make way for a younger man who has got more fight, who will go in with all guns blazing.
"We have been very patient, very polite, but they have let us down. They have let Jeff down and they have let football down."
The couple's daughter Dawn added: "You need someone who is going to fight for the players. (Taylor) takes the industry line and he should take the union line."
Taylor defended himself and his organisation against the Astles' criticism and insisted work is being done on investigating the issue.
"As an organisation we have done more than anyone," he said. "We know that frustration because of the lobbying we have done.
"We are trying to recruit everyone in football to buy into this. We haven't swept it under the carpet. It is an area where we are prepared to commit funding but we can't do it on our own.
"I have never not been prepared to speak with them. It's not neglected, this is high on our agenda."