Jurgen Klopp does not know how the protocol around concussions in football can be improved, but he is sure temporary substitutions are not the answer.

The issue of head injuries has come to prominence again in the past week, most notably after Aston Villa goalkeeper Emiliano Martinez initially played on in the 4-0 defeat to Newcastle United having collided with Tyrone Mings' knee.

Liverpool themselves had to use a concussion substitute – a sixth permanent change, which also grants the opposition another switch – in the Champions League win over Napoli in midweek.

James Milner went down early in the second half, having previously thought, like Martinez, he would be able to continue.

The idea of a temporary substitution, giving medical professionals further time to assess potential concussions, has been floated as a possible solution.

But Klopp, speaking in his news conference on Friday, pointed out the signs of some injuries can be delayed so long players would still be allowed to return to the pitch with a concussion.

"What else shall we do? I know you say 'temporary subs'; I am fine with the concussion sub, absolutely fine," he said before Sunday's match against Tottenham.

"Take him off and bring another player – it means you can still change five times after that, and the other team has an extra sub. I think that's the best we can do.

"You say it takes quite a while between getting the concussion and it really kicking in; I'm not sure then 15 minutes is really the time to wait for it.

"People will tell you after an hour it kicks in. I think how we do it is the right way.

"And it doesn't happen that often, to be 100 per cent honest. I can't remember one before [at Liverpool]. It was the first time with the way Milly got hit, but when did we have a concussion before? I can't remember it.

"We can talk about it like it happens all the time and the boys are constantly in danger. They are not. They are well-trained athletes and it doesn't happen that often.

"But if it happens, we have a solution for it, which is much better than ever before in football's history.

"Is there space for improvement? Probably, but I don't know how."

Milner will not play against Spurs but can return to non-contact training on Monday and a full session on Tuesday "if everything goes well".

Liverpool are at least boosted by Jordan Henderson's recovery from injury and Fabinho's return to form against Napoli.

"The game was a clear sign of Fabinho how we know him," Klopp said of his struggling star. "It was a good game and we defended in all positions on a different level to the week before. It felt good.

"For him, it was very important to realise that that's possible. It was a good start in the right direction."