MARTIN SAMUEL: The attitude towards head trauma in football is baffling

The contrast could not have been more acute. In Bahrain, Romain Grosjean was sending a video message from his hospital bed thanking those in his sport with the foresight to see that the halo to protect the drivers' cockpit would save lives. That day it had saved his.

Meanwhile, in London, Arsenal's doctors passed David Luiz fit to drive home having received seven stitches in a head wound after a collision that left Raul Jimenez of Wolves with a fractured skull. Luiz was told to call in if he got home and felt unwell.

And what if he felt unwell behind the wheel of his car? Why would any development have to occur in the comparative safety of his residence? And why might it not leave him confused or sleepy, and unable to competently make that judgment call?

Gary O'Driscoll, Arsenal's club doctor is widely acknowledged as one of the leading medical professionals with regards to concussion issues in football. His methods, his integrity, has to be trusted. Even so, there seemed a marked difference between sports in their attitudes to health and safety.

And yes, we perceive motor racing to be dangerous and in greater need of safety protocols. Yet F1 drivers are not dying from their involvement in the sport at the rate of retired footballers right now. So football's apparently less stringent take on issues surrounding head trauma is extremely perplexing.

Concussion substitutes. Where exactly is the downside? Here is your player. He has just suffered a significant collision, involving a blow to the head. He may be concussed, he is quite possibly bleeding, as Luiz was.

Why would you not want to replace him, temporarily, with another player who has not received a blow to the head, is not potentially concussed and is not bleeding? It doesn't even have to be a permanent substitution.

If the injured player goes down the tunnel and passes a rigorous concussion test in less urgent conditions, he can return to the field, and his replacement to the bench. Happens in rugby all the time. And rugby union is a sport that only turned professional in 1995. How can it have overtaken one that legalised professionalism 110 years earlier?

No doubt Arsenal's medical staff conducted all necessary concussion checks and were convinced Luiz was unaffected. Yet the macho culture at the heart of sport leaves any diagnosis that involves the contribution of the participant open to question.

Kieron Dyer recalls hearing Dean Ashton trying to run off a knee injury, where the noise of the crunch in the joint was audible with every step. Stuart Pearce played for West Ham on the Saturday having been told by doctors he was out for six weeks. He set up his own fitness test, which involved taking one of the youth players to a far corner of the training field, and booting him up in the air every time he tried to go past him.

Head injuries are no different. Alan McInally said his father Jackie played with a fractured skull. Wore a protective headguard, thought it was harming his game, took it off mid-match. The family used to joke about it every time he forgot something. He died four years ago with dementia.

So sports people can't be trusted. Grosjean admits he was one of the drivers who was against the halo at first - so was Lewis Hamilton.

'The worst looking modification in F1 history,' was his initial verdict. 'There needs to be a certain element of risk,' added Max Verstappen. That's why you do not always listen to the athletes when it comes to safety. It's not their priority; but it should be the priority of the sport.

Luiz came off at half-time, so something was up. Either he changed his mind about continuing, or the medical staff felt he was fragile, but that still left a significant period when he was an accident waiting to happen.

Some of the worst concussion-related injuries, the fatalities, did not occur with the first blow, but with a freakish, coincidental second on the same spot.

Ben Robinson, a 14-year-old schoolboy from Carrickfergus, died because he received two hits in quick succession. Whatever tests Luiz passed, letting him continue with a wound requiring seven stitches jars.

And, yes, we've been here before. Many times. We all love a bloodied hero. The same weekend eyebrows were raised that Luiz continued, other sports lovers branded Daniel Dubois a coward for not wishing to continue getting punched by a 17st 6lb heavyweight boxer on what we now know was a broken eye socket. The world of sport is not without its contradictions.

There is meant to have been surprise within Arsenal's ranks that Luiz played on initially, and further surprise that he was allowed home alone. Yet the biggest surprise is the glacial speed at which the concept of concussion substitutes moves up the agenda.

There was a time when Grosjean would have died. Now he sits in bed lauding the heroes who saved him. Not just at the circuit but in meeting rooms three years ago when they made a decision widely condemned as unpopular.

Football does not even have that excuse. Who opposes concussion subs? Who doesn't support this baby step measure against head trauma? Why is the sport always lapped when it comes to any measure that does not end in rows of noughts?