Head injuries: Football's continuing failure highlighted yet again by treatment of Anthony Martial

It was a truly horrible sight: Anthony Martial staggering off the pitch during the match against Watford this weekend, needing the support of the Manchester United medical team.

Several minutes beforehand he had taken a blow to the head, colliding with Watford's Daryl Janmaat, and was clearly not well at all.

So why was he allowed to play on?

Cynics might wonder whether he'd have been substituted at all had he not been turned inside out a few minutes later by Miguel Britos on the right, allowing Janmaat to put the cross in for Etienne Capoue to score the first goal.

Martial remained face down on the pitch, clearly unable to get himself to his feet.

Brain injury charity Headway have now come out in condemnation of Martial being allowed to play on, suggesting that United didn't follow the required concussion protocol.

The issue isn't so much the blow to the head - a person can recover from that.

But if they're hit again, shortly after that initial injury, the damage can be much worse. A footballer - any athlete - should be removed from danger.

"If the concussed player receives a secondary blow to the head in that time, the damage to their brain could be increased significantly," said charity spokesman Luke Griggs in the Mirror.

"Elite-level football has to set a better example for the millions of youngsters around the world who take their lead from their idols."

That may be true - but more prosaically, elite-level football has to take care of its players.

It doesn't matter whether or not a player wants to continue - if they've taken a whack to the head, they need to be removed from play.

There are four independent match officials there who should be enforcing it.

There are club doctors who have a duty of care to their patients over and above any loyalty they may feel to their employers - and an independent physician in the tunnel who should be stepping in to remove concussed players from the field, as per the new rules that were brought in just two years ago.

And there are coaches and managers who really should know better than to watch a dazed player struggle on in the hope he might "run off" a brain injury.

We've said it time and again - failing to follow concussion protocol is sheer folly.

What's more, it's not showing due care and attention to players. If you don't care about them as fellow human beings, you should certainly care about them as assets to your company.

Jose Mourinho's rather limp response to questions about the extent of Martial's injury was simply not good enough. If onlookers could see that the man was in no state to play, then certainly his manager should as well.

You do not need a medical degree to comprehend that a head injury is always serious - that there is no such thing as a "mild concussion" - and that human beings' welfare must always be prioritised ahead of the potential success of a football team.