Mercedes are hopeful Lewis Hamilton and Valtteri Bottas will avoid grid penalties at the British Grand Prix after their Spielberg woes last Sunday.

Hamilton trails Sebastian Vettel by a point in the battle for the Formula One title after the defending champion retired from the Austrian Grand Prix when he lost fuel pressure.

Bottas also failed to finish the race due to a gearbox issue after starting on pole.

Hamilton was hit with a five-place penalty in Bahrain following an unscheduled gearbox change.

Mercedes technical chief James Allison is optimistic that the Silver Arrows will not face any Silverstone sanctions, but knows they may be punished.

Allison said: "We hope not. We think that both failures were confined to the items which failed and they are both things which can be replaced without breaking into the sealed areas of the car which attract sporting penalties.

"But I say 'we hope not' because every time a car stops in an uncontrolled way where a failure happens and systems are shut down in a way which is unusual, we can't be completely sure until we have done all the necessary checks that all the bits of the car which are sealed and which do attract penalties weren't affected.

"We have got a bit of work on to make sure we are not taking undue risks with parts which might have had some consequential damage when the car was shut down."