Moto2 title contender Marc Marquez has been ruled unfit to ride in Sunday's Malaysian Grand Prix at Sepang.
The reigning 125cc world champion, who trails Stefan Bradl by just three points with two rounds remaining, crashed heavily when marshals failed to warn of a wet section of track in Friday morning practice.
The 18-year-old rookie missed all three free practice sessions to try and nurse his upper body injuries and dizziness, then rode for just three laps in qualifying to claim 36th place on the grid.
However the Repsol Suter rider failed to pass a medical examination on Sunday morning at Sepang and is thus unable to race.
Kalex-rider Bradl, who starts second on the grid behind Thomas Luthi, will thus be crowned champion if he can win the grand prix.
Marquez has won seven races this year compared with four for Bradl, but has also failed to score on four occasions.
German rider Bradl - who regained the title lead with second place last Sunday in Australia, when Marquez rode from last to third - has scored in all but one round.
Tech 3's Bradley Smith, who also crashed due to the wet track in FP1, has already been ruled out due to a fractured left collarbone.