Ruled out of the Indonesian MotoGP after being diagnosed with concussion following the warm-up highside, his fourth accident of the weekend, Marquez began to suffer discomfort with his vision on the journey back to Spain.

Medical checks subsequently confirmed a return (for the third time) of the double-vision problems that kept Marquez off a motorcycle for several months at the end of last year.

The nerve damage to Marquez's right eye is fortunately described as 'less severe' this time, with a further check early this week due to provide an 'estimated recovery period to return to competition'.

"This injury is not like a a broken bone that can be fixed 'mechanically'," said former British champion and grand prix rider Huewen. "An eye injury is for me, being completely non-medical, a bit like a brain injury. It's something that you can't do anything about. It is what it is and you've got to get over whatever the circumstances of it are.

"Every time he falls down - and every time he recovers from this now - he is going to be subconsciously nervous of everything he used to do naturally. This is going to have a compounding effect on his performance and mental wellbeing.

"Unfortunately, for me it's looking like, due to injuries, Marc Marquez is nearing the end of a career that looked like it had a fair way to run. We know his style is to save the unsavable and the ones that he doesn't can turn into quite big crashes.

"I'm very concerned that we don’t do enough about head injuries and concussion in MotoGP. It's a difficult subject because it can be hard to diagnose each individual correctly.

"In Marquez's case, he's had another massive bang on the head and it's caused the eye injury again. How long can he keep doing it? Not much longer, in my view."'s MotoGP editor Peter McLaren said: "It was ten years between the first case of the double-vision on the Moto2 bike in 2011 and the second case last October. Now it's only been five months between the second and third cases, so there's an obvious concern in that alone.

"Just on the human side, most of us will know someone that has been through a long recovery from an injury or illness and then had it relapse. Mentally it must be a horrible situation for Marquez to be in now, having gone through something and then having it all come back again.

"This week's check-up will a big one as far as what happens with Marc this season."

Huewen added: "And this check-up needs to be supervised by someone from MotoGP. I'm sure Marc won't make a comeback before he's 100%, but coming back to the mechanical (bone) injury comparison, in that scenario you can go through a load of pain and might not have the full movement or muscle strength, but are still allowed to ride because you can overcome that situation.

"But if you've got concussion, a brain injury or an eye injury, it's much more difficult to legislate for. Who says his eye is fixed? Riders being riders will ride if they are given an opportunity, particularly if they think they can get around the slight problem they've got.

"So this is going to throw up several questions over the next weeks. Who is checking on the checkers? Who is checking on the guy who says he's okay? What tests are there for this? I feel like we are in a bit of a grey area. I don't know enough about this kind of injury, we're all trying to understand more, but it seems like something that could come back at any time."

Huewen, McLaren and podcast host Harry Benjamin also dive into MotoGP's ban on front ride-height systems for 2023, the post-race 'handbags' between Fabio Quartararo and Jack Miller at Mandalika, Remy Gardner's wet weather helmet woes and predictions for this weekend's Argentine MotoGP.

Download Episode 39 at the following links...

New podcasts available each week.