Marquez was catapulted from his bike on turn seven just before the end of Sunday morning’s 20-minute session at the Mandalika International Street Circuit.
Marquez’s Honda cartwheeled end-over-end as it disintegrated and the Spaniard appeared to land heavily on his left arm at approximately 180kph (110mph).
Marc marquez ?.. speed recovery and hope to see you on race ? https://t.co/ZunzU7a5XT
— Alusia (@lusyy24) 1647752561000
A shaken Marquez got to his feet and walked away before being taken to a nearby hospital for medical checks.
His team Honda said on social media: “Marc Marquez has been declared unfit after examination in local hospital and by the circuit staff and doctors.”
Marquez had already suffered a bruising weekend, having two crashes during qualifying on Saturday, and was thought to have suffered a concussion from Sunday’s spectacular accident.
He had been due to start from 14th on the grid after being promoted one spot due to a three-place grid penalty for Yamaha’s Franco Morbidelli.
BREAKING: @marcmarquez93 will NOT race in the #IndonesianGP ?? https://t.co/AGyv9YCugs
— MotoGP™? (@MotoGP) 1647756894000
Organisers soon after announced the MotoGP race would be reduced from 27 laps to 20 over tyre safety fears caused by the extreme heat at the circuit.
MotoGP has returned to Indonesia for the first time since 1997 at the new venue on the resort island of Lombok, which was partially resurfaced following problems during February’s testing.
Supplier Michelin brought an old tyre casing last raced in 2018 in an effort to combat the conditions.
But Honda and Suzuki riders, in particular, have complained about a lack of rear grip on the tyre with Marquez appearing to suffer more than most.
[email protected] has been declared unfit after examination in local hospital and by the circuit staff and doctors.
— Repsol Honda Team (@HRC_MotoGP) 1647756929000
Track temperatures hit 43 Celsius (109 Fahrenheit) during Sunday’s preceding Moto2 race, which was also shortened from 25 to 16 laps.
“We’ve decided to reduce the distance on safety grounds as a result of the high temperatures,” said a brief statement from the governing body, FIM.
Current world champion Fabio Quartararo will start from pole position for the first MotoGP race to take place in Indonesia for a quarter of a century.