Mercedes insists it must get to the bottom of Lewis Hamilton's recent struggles in the next few weeks, with the team having no answer yet as to why he has been no match for Nico Rosberg recently.
Rosberg rounded off his season in perfect style at the Abu Dhabi Grand Prix with another pole position and dominant victory.
It was his sixth consecutive pole and third consecutive win, to leave himself full of confidence ahead of the winter break.
Mercedes motorsport boss Toto Wolff has said that there is no explanation for why the form has swung against Hamilton in recent races, and it was something that needed to be discovered.
"There has been so much discussion about whether he [Nico] has stepped up his game, or has the car come towards him development wise?" he said.
"Or has Lewis taken it more easy unconsciously – for sure not consciously? I don't know.
"I think we have to do an intelligent list over the next couple of weeks and try to analyse. I think we have to find out.
"But at the end of the day I think for Lewis the world championship title mattered [more], but then those last couple of races were really great driving from Nico."
Hamilton tried new set-up directions in Abu Dhabi last weekend, which included removing a suspension component that had been introduced as part of the development path by the team.
It is suspected that certain changes made to the car after Mercedes' disastrous Singapore Grand Prix may have left Hamilton more unhappy with it, but Wolff is not convinced that may be the only answer.
"I wouldn't say it is the most likely suspicion," he said. "A car is being developed and being improved, and after Singapore we developed in a different direction.
"We took some learning on board after that weekend and whether the car has come more towards Nico and against Lewis I don't know. It could be a factor.
"But I wouldn't want to reduce it on to one single factor, it could be many possible factors playing a role."
Wolff also does not buy the theory that Hamilton simply gave up after clinching the title in Austin.
"I don't think it is something that happens consciously," he said. "I believe that because he is still pushing very hard, still the same guy with the same talent putting the same effort in to, you have to ask. But it could play a role."