Mercedes boss Toto Wolff confirms Lewis Hamilton may need to take another engine penalty before the end of the season.
The Mercedes driver started the Turkish Grand Prix in P11 after taking pole position as he received a grid penalty for changing the Internal Combustion Engine on his car.
With title rival Max Verstappen changing his entire power unit the round before in Russia, both title contenders should now be able to make it to the end of the year without any more penalties.
However, Christian Horner said, "never say never," when asked whether Verstappen could end up with another, and Wolff feels similarly about his driver's situation, although he's optimistic.
"It can last until the end of the season," the Austrian said as per Sky Sports.
"But there could be a moment where we say is it worth taking a fresh one because the other one is still at risk. So this is something that is going to be really a work in progress.
"It's seven [now six] tough races ahead of us," he later added.
"Let's see how the points pan out. I would never say no, but normally, four engines look quite sufficient."
With just six rounds to go, Hamilton currently trails Verstappen by six points as he tries to seal a record eighth World Championship.
If he had to take another engine penalty and start a race towards the back of the grid, it would make that already considerable task even bigger.
He's not worried about that potential scenario, though, saying that it's not his job to do so.
"I don't really give any energy to it," he said.
"It's not my job to worry about that stuff, so I let the guys focus on that, worry about it.
"My engine is in good condition. My first engine, I think, did six races. We still have engine two, and I think engine three is still there as far as I'm aware.
"Hopefully, I don't have to [use a fifth engine], but I can't predict what's up ahead."
The Brit will fancy his chances of retaking the championship's lead at the next round in Austin, with both he and his team enjoying a huge amount of success at the Circuit of the Americas over the years.