Lewis Hamilton suspects Mercedes' sensational Saturday in Melbourne may not be achievable at other tracks and is still unsure if he and George Russell can fight to win the Australian Grand Prix.
Mercedes drivers and officials had been pessimistic in their forecasts for the season prior to qualifying in this week's third race.
But Russell secured a place on the front row alongside Max Verstappen, with Hamilton qualifying third-fastest to put the Silver Arrows in a great position to attack Red Bull's world champion.
"I'm a little bit surprised; maybe they are also a little bit surprised," Verstappen said in Saturday's press conference. "But I guess it's a good thing."
It is certainly a good thing for Mercedes, although Hamilton is not convinced this means all their issues have gone away.
"I think it's perhaps track-specific," he said, "but I think ultimately there's no one in the team that's had their heads down, in terms of giving up.
"Everyone's been working incredibly hard to try to squeeze the most out of what we currently have."
Verstappen had not previously qualified on pole in Melbourne, where he is still waiting for his first win.
Hamilton has a joint-record eight poles at this event, winning twice, and added: "I think this gives everyone in the team a boost and a glimpse of hope and this will spur everyone on and will inspire everyone to continue to push.
"We know that if we can just bring a little bit of performance, we can close the gap to the front. Still, there are going to be places where the gap is a lot bigger."
Russell did not entirely concur, countering: "For sure, we maximised the job, no doubt about it, but we had a good qualifying last week in Jeddah.
"I didn't put my lap together in the last run in Jeddah and was only a tenth off P3.
"So no, I don't think it's necessarily track-specific. I do think we're making some improvement with the understanding of the car."
But Hamilton and Russell were in agreement that Red Bull, even with Sergio Perez encountering issues and failing to make it out of Q1, remain the team to beat.
Russell said: "I do still think Red Bull are a class ahead of everybody else.
"For sure Lewis and I got the most out of it today, [but] by the sounds of what Max is saying, there was probably still a little bit more in the locker.
"And we're talking that three-tenths is a little bit – normally, they're a second ahead; now, they're three-tenths ahead – that's still a huge amount in the world of F1."
If only for this weekend, though, can Mercedes challenge Red Bull for the top step of the podium? Hamilton still does not know.
"I haven't even done a long run," he explained. "So tomorrow, going into the race, will be the first time I do so.
"And I've not seen where we tally up compared to them. We have to expect they're going to be a quarter of a second, half a second, at least, quicker than us.
"But maybe in the tow, maybe we can just about hold on; maybe the fact that there's two of us and only one Red Bull, maybe with strategy, maybe we can apply some pressure to them. So, we'll see."