Montreal Impact player Hassoun Camara has admitted he is "afraid" of the consequences of the concussions he suffered during the 2017 MLS season that have forced him to hang up his boots.
Camara, 33, announced his retirement in an open letter to Impact fans on the franchise's website this week after nearly seven years in Montreal.
The French-born full-back was sidelined as a consequence of the MLS's strict concussion protocol last term after suffering three severe blows to the head, and he told L'Equipe he now fears the irreperable damage his injuries might have caused.
"Yes, I'm afraid, that's true," Camara explained. "When you see the secondary effects it can cause, it's not banal. It's not a toe or foot injury.
"But in the end, I'm quite calm because I have really good people around me. Competent people who know me well are looking after me. The league takes things very seriously in that regard.
"I would have preferred to keep playing, of course. I took quite a few blows to the head last year. I had discussions with the doctors, I did a lot of tests and they showed that I would be taking a risk if I continued playing and didn't recover properly. So I have decided to call it a day."
Following the lead of the North America's major contact sports, MLS is a step ahead of its counterparts on the opposite side of the Atlantic.
Former England captain Alan Shearer recently declared his concerns the damage repeated heading of the ball might have done to his brain, and Camara believes European football has lessons it could learn.
"Coming from Europe, we don't talk much about those things. I was very badly informed about concussion," said the former Marseille and Bastia defender, who suffered his first concussion in 2016 before taking three more severe blows to the head last season.
"Yes, I feel the symptoms, but they're things about which I'd like not to say anything. It hasn't been easy in the last few weeks. I'm lucky to be working on a daily basis with the club, with the physios and all the medical staff.
He added: "In the USA, they pay much more attention to concussion, that's all I know. Recently, I read what Alan Shearer said, and he underlined the importance of more precise diagnosis, to make English clubs aware about this for their players' careers, but above all for after. They're things that can have significant consequences."