Headway made the call after what it describes as “the latest in a long line of incidents that have called into question the sport’s commitment to tackle this important issue”.

Tottenham Hotspur defender Jan Vertonghen collided with teammate Toby Alderwiereld in their side’s home game versus Ajax on Tuesday night.

The events that followed were hugely concerning to Headway which, like a number of other brain injury organisations and charities, has long called for reforms in sport to better handle concussion.

Vertonghen was assessed on the pitch for five minutes, then briefly returned to the match. Shortly afterwards, however, he began staggering and was helped from the pitch. He reportedly said that he had fainted.

Luke Griggs, spokesperson for Headway – the brain injury association, said: “It is hugely disappointing that we are once again talking about concussion rather than the game itself.

“Concussion is notoriously difficult to diagnose. The symptoms may be hidden and require the individual to be honest about how they’re feeling, while they can also be delayed in their presentation.

“Assessing a player for three minutes – or even five, as was the case with Jan Vertonghen – does not allow for medical staff to make a reliable diagnosis, particularly when this is conducted on the pitch under the gaze of tens of thousands of fans eager for the game to resume.

“The pressure on club medical staff is enormous and unfair, particularly in such high-stakes games such as a Champions League semi-final.

“We believe the time has come for football to introduce temporary concussion substitutions that would allow for longer off-pitch assessments to be conducted.

“In addition, independent doctors with expertise in concussion and head injuries should make the ultimate decision as to whether or not a player is fit to continue.

“Not every head injury will result in a concussion. But allowing players to continue while showing clear signs of discomfort following a head injury is contrary to the ‘if in doubt, sit it out’ principle at the heart of all effective concussion protocols.”

Read more from NR Times on concussion in sport:

A sporting chance in school sport concussion fight: How US researchers are breaking new ground in concussion studies.

Tackling football’s inconvenient truth: It’s 14 years since Jeff Astle died of a brain disease caused by heading footballs. Despite evidence suggesting there may be many more similar cases, the fight for action from the game’s authorities goes on.

Rugby’s battle with concussion threat: An interview with the RFU’s chief medical officer Dr Simon Kemp.