A slightly nervous Mercedes is preparing for this weekend's Russian Grand Prix.
Actually, the usually utterly dominant German squad can wrap up the 2015 constructors' world championship this weekend at Sochi.
But although the silver cars finished easily first and second at Suzuka, the points gap between leader Lewis Hamilton and Sebastian Vettel's Ferrari is 59 points - meaning the German driver is still in the running with five races to go.
Not only that, Vettel - although surprisingly - won quite dominantly just over two weeks ago in Singapore, and it is believed Mercedes is still not entirely sure what caused the slump.
"I keep getting asked about that actually," smiled technical boss Paddy Lowe. "It's not a simple answer at the end of the day.
"We definitely learnt some lessons from that and we still have a lot more to learn."
Niki Lauda, Mercedes' team chairman, admitted to relief after Suzuka that the Brackley team so quickly returned to form, but he has also admitted that he is worried Sochi this weekend could once again expose the W06's weakness.
Mercedes finished one-two in Russia last year, but for the sport's return in 2016, Pirelli has changed its tire selection and will now offer the two softest tires - the same ones that were fitted when Mercedes slumped in Singapore.
And Lowe thinks Pirelli may have been influenced in its choice after Nico Rosberg last year managed to complete "almost the entire race on a single set of tires."
"One year on, the track surface will have weathered differently so we must ensure we have all eventualities covered," he said.
Meanwhile, Ferrari is not counting on having another Singapore-like showing this weekend at Sochi.
Just over two weeks ago, Sebastian Vettel put himself back in the championship reckoning by dominating in Singapore, where Mercedes famously 'slumped.'
But the silver team was back at its dominant best a week later in Japan.
Still, there are reasons for Ferrari to be happy with its progress, after ending the poor form of 2014.
"We have certainly seen positive signs," said team spokesman Alberto Antonini, "but we know there is still a lot to do."
Kimi Raikkonen, Ferrari's common link in the resurgent transition from last year to 2015, has even been surprised by the progress made this year.
"Before Monza we thought it would be a hard race for us, but it was actually pretty good," he is quoted by Speed Week. "Suzuka was also not bad even though it is not theoretically good for us.
"This shows we are moving in the right direction," added the Finn.
And so to Sochi. Team boss Maurizio Arrivabene said: "I think we will be not so strong because the grip is low, but we should be on the pace in Austin.
"Mexico is an unknown for everyone, because F1 has not been there for more than 20 years. Brazil I would rate as 50-50, but we should be able to exploit the qualities of the car in Abu Dhabi."
One thing going for Ferrari in Russia is that Pirelli is rolling out the softest tires in its range, which so far in 2015 have worked out well for the Italian team.
But spokesman Antonini warned: "Although at previous appearances this (tire) choice suited us, we can expect to encounter very low levels of grip at Sochi.
"Even though we are approaching the end of the season, it's not yet time for us to assess what we have done, because that can wait until the championship is over."
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