Former England hooker Steve Thompson revealed he can no longer remember winning the World Cup because of brain injuries he suffered playing the game as he joined a group of ex-internationals planning legal action for negligence against the rugby authorities.
Thompson, 42, is part of a 'test group' for a potentially much larger action along with another former England player, Michael Lipman, and ex-Wales international Alix Popham, according to Rylands Law, the firm leading the case.
The planned action is against World Rugby, the Rugby Football Union and the Welsh Rugby Union, for "failure to protect (the claimants) from the risks caused by concussions".
Thompson was diagnosed with early onset dementia and probable CTE (chronic traumatic encephalopathy) in November.
"I have no recollection of winning the World Cup in 2003 or of being in Australia for the tournament," he said.
"Knowing what I know now, I wish that I had never turned professional. I went from working on a building site and training twice a week to training every day, sometimes twice a day.
"Many of those training sessions were contact sessions using a scrummage machine and I would be in the thick of things, with all the pressure pushed on me.
"It was not uncommon for me to be left dazed, seeing white spots and not knowing where I was for a few seconds, sometimes I would pass out completely.
"It was just an accepted part and parcel of training.
"I really wished that I had ended my career earlier, maybe my diagnosis might not be so bleak."
Popham, 41, was diagnosed with traumatic brain injury, early onset dementia and probable CTE in April.
"I had a great career and willingly gave my heart, body and soul to rugby. I just didn't know I was giving my mind too," he said.
Lipman, 40, who was diagnosed with early onset dementia and probable CTE three weeks ago, described himself as "a walking time bomb".
Thompson, Lipman and Popham are part of a test group of eight players, but Richard Boardman from Rylands Law says he is representing more than 100 players whose ages range from their 20s to their 50s, many of whom are showing symptoms of neurological problems.
"The vast majority of the former players we represent love the game and don't want to see it harmed in any way," Boardman said.
"They just want to make it safer so current and future generations don't end up like them. This is why we're asking World Rugby to make a number of immediate, relatively low-cost changes.
"The obvious first step is for World Rugby, RFU and WRU to stop being in denial and acknowledge that there is a problem."
World Rugby told BBC Sport: "While not commenting on speculation, World Rugby takes player safety very seriously and implements injury-prevention strategies based on the latest available knowledge, research and evidence."
The WRU told the PA news agency that, as it has had "no direct communication on the subject", it would "just like to support the World Rugby comment", while the RFU has also been contacted for comment.
The players have also created 15 'commandments' which they feel World Rugby should adopt to make the game safer.
These include an acknowledgement from World Rugby that playing the game can lead to CTE and other neurodegenerative diseases, the abolition of zero-hour contracts which compel players to play when injured in order to get paid, a limit to the number of contact sessions permitted in training, better sideline testing and more considerate use of substitutions.
The announcement cited the example of the 'bomb squad' scenario in the 2019 World Cup final where six 18-stone South Africans came off the bench in the second half.
The group are also calling for a central database to record head injuries, better aftercare for retired players and the removal of the reliance on MRI scans to rule out brain trauma.
