Brain injury charity Headway has demanded action from UEFA after Switzerland defender Fabian Schar was allowed to play on having suffered a concussion.
The Newcastle United star was knocked unconscious as he clashed heads with Jemal Tabidze early in Saturday's Euro 2020 qualifier against Georgia in Tbilisi.
Despite requiring treatment for an extended period, during which time Jano Ananidze reportedly prevented Schar from swallowing his tongue, the defender was permitted to continue playing.
Schar had a key role in both goals in a 2-0 win, but Headway is furious that an "incredibly dangerous" risk was taken with the player's wellbeing.
Charity chief Peter McCabe said: "What is it going to take to make football take concussion seriously?
"How many more players will have their careers and, more importantly, their lives and long-term health put at risk by the sport's inability to follow its own protocols?
"Put simply, the decision to allow Fabian Schar to return to the field of play after suffering a clear concussion was not only incredibly dangerous, but also a clear dereliction of duty.
"The player's comments after the match are also deeply disturbing and again show the lack of awareness and understanding among players.
"UEFA must immediately launch an investigation into the incident and explain why their protocols were not followed."
Upon seeing footage of the incident, Schar told Blick after the match: "It looks awful. I can't remember anything. I was out for a few seconds.
"My skull is still humming and I've got neck ache and a bruise on my forehead, but it was worth it."
Following the incident, Schar has been withdrawn from the Switzerland squad as they prepare to host Denmark on Tuesday.