Mercedes boss Toto Wolff has not ruled out Lewis Hamilton taking another fresh engine over the remaining rounds of the 2021 season.
Hamilton moved on to his fourth Internal Combustion Engine of the campaign at the Turkish Grand Prix and, after he topped qualifying at Istanbul Park, the subsequent penalty will drop him to 11th on the grid for Sunday's race.
It marks a different approach to title rival Max Verstappen, who took on a completely new power unit, including ancillary components, last time out in Russia.
Hamilton's teammate, Valtteri Bottas, is already on his fifth engine of the season, with reports emerging that the unit fitted to his car at the Italian Grand Prix is no longer useable, amid apparent reliability concerns.
With seven races remaining, including Sunday's 58-lap encounter at Istanbul Park, Wolff could not guarantee Hamilton making it to the end of the season using his current engine pool.
"I would very much hope not, but it's seven tough races that are in front of us," Wolff told Sky Sports, when asked if there is a "real chance" Hamilton may have to take a fifth engine, as Bottas has already done.
"Let's see how the points pan out. I would never say no, but normally four engines is good – it looks quite sufficient."
Wolff expanded on the issues Mercedes have encountered with their power units this season.
"We are not looking at stockpiling good engines, [as] that would be silly in taking such a penalty," he said of the recent changes.
"It's just we've seen over the course of the season that we had some little gremlins, that we weren't completely sure where they came from, and how much performance they could potentially cost.
"We'd rather have a new engine in the pool, that we understand, that can possibly go longer."
Lewis Hamilton claimed his 100th Grand Prix win to move into the championship lead, but it's Red Bull and Max Verstappen who will be happiest after the Russian Grand Prix.