Carlos Sainz was ruled out of the Qatar Grand Prix one hour before the formation lap after Ferrari found a fuel system issue on his car.
Sainz was due to start 12th on the grid following a scrappy qualifying session on Friday but will sit out of the race after the team was unable to fix the problem in time for the start.
The Spanish driver is the only non-Red Bull driver to win a race this season and ahead of the Qatar Grand Prix was fifth in the drivers' standings.
It is also a blow for Ferrari, which has been closing the gap to rivals Mercedes for second place in the constructors' championship over the last four rounds. The gap stands at 26 points ahead of the race.
Sainz's teammate Charles Leclerc will start the race from fifth while Mercedes' drivers George Russell and Lewis Hamilton line up second and third on the grid.