Mercedes boss Toto Wolff has explained why Lewis Hamilton was forced to replace his engine and take a grid penalty on Sunday, refusing to rule out a repeat before the end of the season.

The Briton's 10-place penalty after topping qualifying contributed to a fifth-place finish at the Turkish Grand Prix, with team-mate Valtteri Bottas winning and title rival Max Verstappen finishing second to move six points clear of Hamilton in the championship standings.

However, Wolff revealed that the team felt they had no choice but to take a new Internal Combustion Engine (ICE) due to issues with Hamilton's previous power unit.

He insisted there had been no tactical timing to the decision, which was needed for technical reasons.

"We had to do it," Wolff told Sky Sports. "We saw some data on the Internal Combustion unit that didn't look very promising and a DNF is a total killer for the championship.

"We've seen over the course of the season that we've had some little gremlins that we weren't completely sure where they came from and how much performance they could potentially cost.

"So we'd rather have a new engine in the pool and that we understand that can possibly go longer.

"I think we understand much better now where the root cause lies and it's something that can happen from time to time if you just have a material issue, a batch problem and these are the things you need to consider."

The replacement power unit was Hamilton's fourth of the season, but Wolff suggested that it was not beyond the realms of possibility that he would be forced to take a fifth before the end of the campaign.

"The fourth one can last until the end of the season but there could be a moment where we say is it worth taking a fresh one because the other one is still at risk," Wolff continued.

"So this is something that is going to be really a work in progress."

There are six races to go in the 2021 Formula One season, a run that starts with the United States Grand Prix - an event Hamilton has won a record six times - on October 24.