Lewis Hamilton's Mercedes F1 engine was damaged in Brazilian GP

At one stage during the Interlagos race Mercedes personnel declared that a failure was imminent, but some quick work in the pit garage and back at the engine base in Brixworth, plus Hamilton's adjustments in the cockpit, helped to ensure that it got to the flag.

However the team has now acknowledged the engine sustained some damage, although it won't know any details until it inspects it further.

That unit, the third that is allowed without penalty, was supposed to be used by Hamilton during the Abu Dhabi weekend, and even if an inspection pronounces it healthy, the team may still have some concerns in terms of how hard it is used during the weekend.

Hamilton still has the use of his power units from earlier in the season, but both have done seven race weekends, and have accumulated a lot of mileage.

If the team opts to take any new elements, Hamilton would have to take a grid penalty - but he would have the latest specification and be able to push its performance to the maximum for the final race of the season.

Chief strategist James Vowles confirmed that the extent of the damage is unknown.

"If we just go back a little bit and look at what happened in the race, after the first pitstop with Lewis we noticed quite a significant problem, which required a huge amount of input from a number of sources," he said in a Q&A with fans.

"We have a team back in the UK at Brixworth who work alongside us on the intercom, and we have a huge team trackside working together diligently to understand what we can change on the engine to get to the end of the race.

"They did a fantastic job. It wasn't one change, it was a huge number of changes across a 40-50 lap period, where they were working with Lewis to adjust various componentry and get that power unit to the end of the race. They did a fantastic job.

"The net result of that, though, is that the engine has sustained some level of damage, but we don't yet understand what.

"It has to be inspected and understood before we can make any decision going forward to Abu Dhabi."