Daniel Ricciardo's run of five successive podium places looks to be in danger of ending after the gearbox on his car was replaced ahead of the British Grand Prix, incurring an automatic five-place grid penalty.
Gearboxes must last for six races and the one in the Australian's Red Bull, which was swapped out before Saturday's final practice, had not done so.
Ricciardo won in Azerbaijan in late June and finished third in Austria two weeks ago.
It was his second grid penalty of the season, after a similar five-place drop in his home race in Melbourne in March. He started from the pit lane on that occasion and failed to finish the race.
Mercedes rival Valtteri Bottas, who won in Austria from pole position, also has a five-place penalty for Sunday's race after a similar gearbox change.
Briton Lewis Hamilton, who had a five-place drop in Austria, is chasing his fourth successive British Grand Prix win and fifth in total.
There has been increasing debate this season about the fairness of penalising a driver for mechanical problems beyond his control, although Formula One has always been a team sport.