Ablett snr played 248 AFL games, booting 1031 total goals to become the sixth-highest goal scorer in league history and one of the best to ever play.
But, as the 61-year-old's lawyer Michel Margalit claims, those games came at the cost of physical and mental well-being.
"He really struggles on a daily basis," Margalit told The Age.
"It is very typical symptomatology you see from players, or athletes, who suffer these concussion-related injuries around the world.
"There is everything from memory loss to being unable to work and many other symptoms."
The AFL Great's legal team have said that he undertook scans last year that revealed brain damage.
Allegedly unable to work due to his condition, Ablett snr seeking damages, interests, and costs from his former clubs and the league.
It is claimed that he is unable to fund his medical treatment.
"One of the biggest challenges for Gary is he very much is left without the means and ability to fund the care he now requires, given his condition," said injury lawyer Margalit.
"This is really why he's been forced, in a sense, to bring the claim; to be able to afford both the medical expenses and medical care he requires — and those costs will only continue to increase."
Ablett Senior played just one season with the Hawks, and 13 with Geelong, believing he was concussed "eight or nine times" during his career.
Speaking to The Herald Sun earlier this year, the 61-year-old provided details on his condition.
"I told him of my concerns and Peter helped organise a MEG scan that American Military use. It showed I have significant structural and functional brain damage," Ablett snr said.
"I've since been seeing a psychiatrist named Dr John Perica once a month and receiving some new medical treatment that's been helping reduce the headaches and improving my mood."
This legal action is one of three ongoing battles with the AFL's concussion policy.
A class action, signed by around 60 former players, is seeking compensation for the trauma and medical expenses caused by concussion.
Former premiership Bulldog Liam Picken, like Ablett snr, is also suing the league and his old club over ongoing health issues linked to concussion.