Lewis Hamilton will receive a five-place grid penalty for Sunday's Austrian Grand Prix as a result of an unauthorised gearbox change.
Teams must run a gearbox for six consecutive events but Hamilton's was changed before that period had expired.
Stewards have not confirmed the penalty but Hamilton's Mercedes team have accepted it is inevitable.
It is a blow to Hamilton's attempts to close the championship deficit to Ferrari's Sebastian Vettel.
On Friday, Hamilton was
fastest in the second practice session, ahead of title rival Vettel.
Hamilton was 0.147 seconds quicker than Vettel at the Red Bull Ring, with the second Mercedes of Finland's Valtteri Bottas 0.216secs off the pace.