Toro Rosso drivers Pierre Gasly and Brendon Hartley will face grid penalties at this weekend’s Russian Grand Prix after Honda confirmed it will introduce its latest Formula 1 engine upgrade.

The Japanese manufacturer has made impressive progress in its new partnership with Toro Rosso this season but the update will mark its first power unit specification change since the Canadian Grand Prix in June.

Honda’s brand new Spec-3 engine will be available to Gasly and Hartley, meaning both drivers are likely to start from the back row of the grid in Sochi with long-term performance key to the decision.

As a result of taking on the upgraded engine in Russia, Toro Rosso's drivers should in theory avoid further penalties at the upcoming Japanese Grand Prix, which marks Honda's home race. 

Toro Rosso’s last significant update came at the Austrian Grand Prix in July, leading to calls from Hartley for further upgrades following a lacklustre performance in Singapore.

Red Bull driver Max Verstappen is also set to be hit with a grid penalty for engine changes in Russia following a recurring power unit reliability issue throughout the Singapore race weekend.