Mercedes has fitted a new internal combustion engine to Bottas’ car for the Austin race, marking the sixth new ICE component the Finn has been forced to use this season. 

The reigning world champions are trying to “contain” an issue with its power unit, having previously admitted to having “question marks” over its engine. 

Bottas has now used twice as many engines than his permitted allocation, with Mercedes also installing new power units in his car and taking engine penalties at Monza and Sochi. 

Bottas’ Mercedes teammate Lewis Hamilton also introduced a new ICE into his pool at the Turkish Grand Prix last time out. 

Williams driver George Russell and Aston Martin’s Sebastian Vettel have also moved onto their fourth power units of the 2021 season.

Both drivers have also had new turbochargers and MGU-H elements fitted, meaning they will consigned to back-of-the-grid starts for Sunday’s race. 

Bottas, Russell and Vettel have moved onto a new exhaust system, though all three are within their allocation of eight components for the season and therefore will not take penalties for the respective changes.