With Mercedes admitting to having some “question marks” over the reliability of its 2021 engines, the reigning world champions have decided to instal a new internal combustion engine (ICE) on Hamilton’s car. 

That will result in an automatic 10-place grid drop for Hamilton for exceeding his permitted allocation of engine components and means 11th place is the highest position the seven-time world champion can start on Sunday, providing he sets the fastest time in qualifying. 

Mercedes could yet decide to change more elements of Hamilton's power unit and such changes would incur a bigger grid drop. 

Hamilton holds a two-point advantage over Red Bull’s Max Verstappen heading into the final seven rounds of the 2021 season. 

Mercedes has also elected to change the exhaust on Hamilton’s car, though there will be no penalty as it is within his permitted allocation being only his third component of the season. 

The fresh power unit gives Hamilton a third engine in his pool to see him through to the remainder of the season, having lost an engine in his on-track stoppage during practice at Zandvoort.

The FIA also confirmed on Friday morning that Ferrari has fitted a new power unit on Carlos Sainz's car. 

Sainz will start from the very back in Istanbul after taking a new ICE, turbocharger (TC), MGU-H, MGU-K, energy store (ES), control electronics (CE), as well as a fresh exhaust.