George Russell believes that Suzuka's high-downforce environment coupled with the track's long straights has "exposed" the weakness of Mercedes' draggy W13 car.
While everyone was happy to enjoy a dry qualifying on Saturday, Mercedes struggled for pace in the all-important sessions, with Lewis Hamilton and Russell concluding their Q3 shootout a disappointing sixth and eighth respectively, a second on average behind pace setter Max Verstappen.
In Japan, Mercedes opted for a high downforce configuration well-suited to Suzuka's first sector dominated by a sequence of narrow sweeping medium and high-speed corners.
But according to Russell, that set-up only served to underline the weakness of Mercedes' car on the track's long straights, a familiar theme for the Brackley squad this season.
©Mercedes
"We've known this year we've not had the most efficient car, very draggy, and this is the first high downforce circuit where you have long straights as well," Russell said after qualifying.
"Normally when you look at high downforce circuits, the straights are relatively small and there's not that chance to get those straight line deltas as well.
"I think we're probably losing seven or eight-tenths to Red Bull in the straights today, and the circuit has exposed that weakness of ours.
"But it's not the first time this season. There's quite a theme that we have difficult Saturdays."
Mercedes technical director Mike Elliott said the team's under-performance at Suzuka wasn't entirely a surprise although it was a bit worse than expected.
"I think we're a bit disappointed with the performance, but we weren't expecting it to be a really good circuit for us," said Elliott.
"We expected it to be a bit more challenging. Where we want to run the car optimally in downforce level appears different to where others want to run, and that's part of the way we've developed the car and part of what we need to adjust over the winter."
©Mercedes
Hamilton felt that, come rain or shine on race day, Mercedes will be at a deficit against Red Bull. But the seven-time world champion admitted that a wet day would perhaps throw a few opportunities his team's way.
"It's not going to be great with our car and no DRS," he said. "I think Red Bull is still quicker with no DRS on the straight than us when we have DRS open. But we'll be quick through the corners.
"The rain always opens up more opportunity. I think it could be not the most exciting race if it's dry. At least not for us, overtaking."
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