Like his fellow Honda riders, after a strong test at the new Mandalika circuit in February, Marquez struggled on the modified Michelin rear-tyre casing brought for the race weekend and last used in 2018.

The Spaniard had already fallen three times in practice and qualifying, leaving him 14th on the grid, but the near 200km/h highside in morning warm-up was on another scale.

As Marquez entered the last of the fast Turn 5-6-7 right-handers, the rear of his machine kicked out and then dug in, sending him somersaulting through the air before landing hard on the asphalt runoff.

Marquez's recent injury battles heightened the concern over his welfare, but the 29-year-old was eventually able to stand and stagger slowly out of the gravel.

Arriving back in the paddock on a scooter, the eight-time world champion was initially sent to the medical centre before being transferred to a local hospital for further checks.

“What can I say? It has not been our weekend, we have struggled and had problems from the start," said Marquez.

"It was a really big crash in warm-up this morning, maybe one of the biggest I have had.

"I went to the local hospital and while there were no serious problems - it was decided that I should not race.

"It’s of course a shame, but the best decision.”

While the concussion diagnosis ruled Marquez out of what became a delayed, wet race, further precautionary checks will be carried out when he arrives back in Spain.

"It was a big crash, a big concussion on the head, so normally this type of accident you need some time to recover," said team manager Alberto Puig.

"It would not be a very safe idea to send him on the bike so we all decided that the best thing to do was to skip this Grand Prix and try to recover and see the evolution [of his physical condition] in the next 12-24 hours.

"No pain, but he had three strong crashes this weekend and the one today was massive. So it's not that he has something broken but it's not very comfortable and when you hit your head you have to be more cautious than if you hit some bone."

Team-mate Pol Espargaro went on to finish twelfth, in a race won by KTM's Miguel Oliveira.

The unpredictable podium line-up so far this season means that, despite the DNS and modest fifth place in Qatar, Marquez is still within 19 points of title leader Enea Bastianini, who has scored 30 out of a possible 50 points.

Round three takes place at Termas de Rio Hondo, Argentina, on April 3.