Hamilton topped both practice sessions at Istanbul Park on Friday but the seven-time world champion will be hit with a 10-place grid penalty after Mercedes opted to install a fresh internal combustion engine into his car for this weekend. 

With Mercedes concerned about the risk of a reliability failure in the final seven races of the season having admitted it has “question marks” over its engine, the world champion team has decided to take the hit of a grid demotion in Turkey. 

Mercedes head of trackside engineering Andrew Shovlin said earlier on Friday that the call had been made after detailed simulations on upcoming tracks suggested that Turkey was the best place to be able to recover from such a penalty. 

But Red Bull team principal Christian Horner is convinced Mercedes had no choice because of increased fears about reliability following a number of recent setbacks.

“I think it was probably, from what we understand, more of a forced choice rather than a selected choice,” Horner told Sky Sports F1. “We’ve seen they’ve had issues with some of their other teams as well. 

“It doesn’t affect us and what we’re doing but it shows how tight and tough it is to get to the end of the season on three engines, that neither of us have managed. So hopefully we can do it on four.”

Mercedes has been forced to change Valtteri Bottas’s engine twice at the last two races, while its customer teams have also taken similar penalties, with Williams driver Nicholas Latifi moving onto his fourth PU in Russia. 

Horner also reckons Mercedes is gambling by only choosing to fit a new ICE in Hamilton’s car, rather than taking the opportunity to introduce a complete set of fresh components into his pool and start from the very back. 

“You can do all the sims and modelling you like and then something variable happens,” Horner said. 

“There’s no such thing as total stability of a situation like you have in a simulated world, to the end of the year. So there could be other twists and turns in this. Let’s wait and see. 

“Obviously we’ve taken a penalty, we’ve put ourselves into a good position. We’ve taken the additional parts as well, the battery, the MGU-K, the H. 

“Lewis has just taken the ICE, the combustion, that obviously is less of a penalty but it’s still going to put a lot of stress on those other components to the end of the year.”