Crystal Palace boss Roy Hodgson would support the idea of introducing a fourth substitute to allow players to be assessed for concussion.

The debate over concussion in football was ignited this week after Tottenham defender Jan Vertonghen suffered a nasty clash of heads during Spurs’ Champions League defeat to Ajax on Tuesday.

The 32-year-old briefly returned to play following treatment but quickly signalled he was unable to continue and was helped from the pitch by two members of Tottenham’s medical staff.

Tottenham say Vertonghen passed all concussion tests on the pitch, while a scan on Wednesday revealed nothing untoward.

However the incident has led to calls for a fourth substitute to be introduced, which would allow players to temporarily leave the pitch for assessment over a possible concussion.

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Such a scenario is already in place in rugby, where players can be taken off to undergo an HIA (head injury assessment) before returning to the field of play if fit.

And when asked if he would support football introducing a fourth substitute for concussion, Hodgson said: “Yes, I wouldn’t see anything wrong with that at all.

“I mean we are going to get to that stage; the game is becoming much more of an 11-man game for 90 minutes and you have got a sub up your sleeve in case someone gets injured.

“We are going towards bigger groups of players, 25 players in a squad now rather than 18 or 19 that it might have been sometime ago.

“So I think we are moving definitely towards more substitutes anyway with the pace of the game.

“Certainly if something could be introduced whereby someone could maybe go on the field and prevent a hastier decision vis-à-vis the state of the concussion then is maybe going to happen at the moment when the doctor is under that enormous pressure, I cannot imagine anybody in football would say we don’t agree with that.

“But of course it is up to the authorities to decide if that is a good plan or not.”