Former rugby union centre Adam Hughes says the concussion protocols in the early part of his career were "crazy" but believes they have improved.
Hughes was forced to retire in 2018 at the age of 28 due to a brain injury.
Ex-players including Alix Popham and Steve Thompson have early onset dementia and claim the sport has left them with permanent brain damage.
"There were times where I suffered concussions and I was always playing again a few days later," Hughes said.
"You look back now and think that was crazy, what was I doing? Because these days you wouldn't dare play for another few weeks at least with all the tests involved.
"But at the same time you only know what you know don't you and you don't know what you don't know."
Former Wales back-row Popham, 41, and ex-England hooker Thompson, 42, are part of a group of eight former players in the process of starting a legal claim against the game's authorities for negligence.
Global governing body World Rugby and the Rugby Football Union (RFU) have told BBC Sport they take "player safety very seriously". The Welsh Rugby Union (WRU) said it "supported and endorsed the World Rugby comment on the subject".
The Welsh Rugby Players Association told BBC Sport Wales: "Player welfare is an absolute priority for us. As such we do have medical professional representation on the WRU's medical committee to ensure guidance around player safety is implemented across the professional game here in Wales.
"We will continue to liaise with these experts and will do so in the coming weeks on this very important subject. It is important we follow the science to ensure we can play our part in enforcing measures that protect our members now and into the future.
"We have taken some recent steps forward in player welfare and are currently in the process of launching a pilot programme, which provides medical aftercare services for our members.
"We will also continue to support current and retired players through the work we currently do and our charity Second Half Rugby which supports players in times of hardship."
In 2011, a group of former American football players started a class action against the NFL and won a settlement worth about $1bn (£700m).
World rugby could now face a similar landmark case and, if the class action is successful, could force change to the way the game is played.
'Learned so much in 10 years'
"With the research that's gone on it's all about finding now what did the authorities and the governing bodies actually know at those times, when those guidelines were in place, compared with what we know now," former Dragons player Hughes told BBC Sport Wales.
"Precedents were set with the NFL a good few years ago and then the NHL followed not so long after.
"I think you'll find most concussion sports will follow now in that route.
"It's a really tough one because we've learned so much in the last 10 years, but we also know that there were times in sort of the 2010-2013 era - which was the early part of my career - where the protocols were a bit up in the air.
"That's the issue we have is, yes, we all know the risks of going out there and playing rugby, everyone knows that.
"It was about how we were looked after once those injuries were suffered, and the people who were in the know and the people who had control and how they controlled those guidelines to make sure the players were safe. That's the main concern, really, with this lawsuit."
Popham, who in an emotional interview that included his wife, Mel, told of the memory loss and mood swings that have accompanied his early onset dementia, and his fears he may not be there in the future for his young family of three girls.
Hughes sympathises with Popham's plight and at the same time has his own concern that he could also be in danger of developing similar symptoms.
"It does make you a bit nervous. I've got another 10 years until I reach the same age as Alix, so you worry about how the net 10 years will go knowing what he went through," Hughes said.
"But I hold in my back pocket that I think I made the sensible decision to retire early, I didn't push it too long.
"But when you hear about Alix and the stories in those interviews it's quite shocking and you hope yourself, the decisions you made, would help you avoid that."
More information about dementia and details of organisations that can help can be found here.