Lewis Hamilton set for Austrian Grand Prix grid penalty

Mercedes has had to replace the gearbox with which Hamilton finished the Baku race a fortnight ago.

The team discovered damage to the unit after the Azerbaijan GP and decided not to risk running it again in Austria.

It is unclear if the Hamilton damage was related to the hit from behind that he suffered when Sebastian Vettel ran into him in their controversial incident under the safety car.

As he has not completed six races with the gearbox, Hamilton will inevitably be penalised.

The FIA revealed that Mercedes informed the officials on Tuesday morning.

A note from the FIA technical delegate Jo Bauer said: "The above driver did finish the last race in Baku and this gearbox change was before the six consecutive events expired.

"As this is not in compliance with article 23.5a of the 2017 Formula 1 sporting regulations, I am referring this matter to the stewards for their consideration.

"The team informed the technical delegate about the gearbox change on Tuesday, 04th July 2017, at 11:29 hours."

Hamilton had been fastest in both Friday practice sessions at the Red Bull Ring.

He comes into the weekend 14 points behind championship leader Vettel.

Meanwhile, Ferrari has utilised its 'joker' to make a gear ratio change.

Red Bull made its one allowed change for the last race in Azerbaijan.