The German is still seeking his first victory of the season as Ferrari bids to get on top of the set-up issues that have held back its challenge against Mercedes over the first half of the campaign.

But its situation will not be helped if Vettel is forced to drop down the order after qualifying.

Motorsport.com has learned that Ferrari is conducting a detailed investigation of Vettel's gearbox amid fears it picked up terminal damage in Baku.

Although the team is hoping that it will be able to get the green light so the unit will not be replaced, fears are growing that it cannot be run again.

A final decision can wait until Friday, however, with drivers able to use a different gearbox in the practice session from the unit that they use over the remainder of the race weekend.

Additional reporting by Roberto Chinchero