Russell to join Vettel at back of USGP grid

George Russell will join Sebastian Vettel at the back of the grid for the United States Grand Prix after becoming the latest Mercedes-powered driver to be hit with power unit penalties.

Aston Martin and Vettel confirmed on Thursday the four-time champion would be taking new power unit elements for the event at the Circuit of the Americas in Austin.

For Sunday's race, Vettel will have Williams driver Russell for company on the back row as he has also exceeded his permitted allocation of certain PU components for the season.

Both drivers have a new internal combustion engine, turbocharger and MGU-H.

The duo are now the fourth and fifth drivers respectively who rely on Mercedes power to take grid penalties due to issues with the German manufacturer's units this season.

Works driver Valtteri Bottas took penalties in Italy and Russia, with Daniel Ricciardo and Lewis Hamilton following suit in Turkey.

Seven-time champion Hamilton, however, only required a new engine rather than multiple components as was the case for the McLaren driver.

Under the regulations, teams are allowed to use no more than three of each component within a power unit.