McLaren has encountered considerable issues with the Honda power unit this season following the Japanese manufacturer’s return to F1.

For the race at the Sochi Autodrom double world champion Alonso will serve a 25-place grid penalty as four elements of the power unit have been replaced as part of a Honda upgrade.

Initially, four elements of the power unit have been replaced as part of a Honda upgrade.

It has been confirmed by the FIA that Alonso collects a 10-place penalty for requiring a 10th internal combustion engine, plus five places apiece for a ninth turbocharger and MGU-H, and a further five places for a seventh control electronics.

In addition, two additional changes have been referred to the stewards for consideration as McLaren has since added a 10th turbocharger and MGU-H, both of which will incur five-place penalties.

UPDATE: The FIA has confirmed 10 places’ worth of further penalties for those items, meaning an official grid drop of 35 positions, although in practice it will simply be a back-of-grid start.

Alonso’s Spanish compatriot Merhi serves a 20-place penalty.

The Manor driver drops 10 places for using a fifth internal combustion engine, plus five places for a fifth turbocharger and MGU-H.

Merhi is back in the car this weekend having sat out the last two races after the team agreed a deal with Alexander Rossi to drive in five of the final seven grands prix of this season.