George Russell retired from the Bahrain Grand Prix in Malaysia last weekend with a power unit problem five laps from the finish while he was in third place. (EPA Images pic)

SINGAPORE: George Russell is set to start from the back of the grid in Singapore this weekend in another big blow to the unlucky Mercedes driver's rapidly fading Formula One world title hopes.

The team confirmed on Tuesday that the Briton had no engines left in his season's allocation of four and would have to take a new one for the sprint weekend, with the corresponding penalties likely sending him to the back row for Sunday's race.

Russell retired from the Bahrain Grand Prix in Malaysia last weekend with a power unit problem five laps from the finish while he was in third place.