Although a final decision will be taken by the team on Friday morning, both drivers are bracing themselves for the worst and could find themselves relegated to the back of the grid.

Hartley's situation appears clear after the engine failure that put him out of the Mexican Grand Prix, while Gasly, who managed to finish the last race, also expects to need some new elements for Interlagos.

"It is not confirmed yet, but it looks like it," explained Gasly about the prospect of an engine penalty.

"It looks like we will have to start from the back of the grid, which makes it of course pretty difficult. But it is something that we cannot really change.

"We have to accept it if we take it. But it doesn't change the target in the end, it just makes it a bit tougher."

Having faced engine penalties in Mexico for new power unit elements, Gasly admitted that the situation was difficult for him to accept.

Asked about what he had found toughest about F1, the Frenchman said: "Having to in a way accept all the penalties you can have. It is something I was never used to having in the lower series.

"There, when you qualify in a certain position, you are sure to start in that position. But here sometimes, even if I did not do qualifying in Mexico, we knew already that unless we qualified in the top three we would be starting from the back of the grid.

"It is something that is a bit difficult to accept, but that is the way it works."