Lewis Hamilton says he is still aiming for a podium finish in the Singapore Grand Prix, but doubts Mercedes will find a solution to its problems for the race.
The Briton, who had started from pole position in the last seven races and in 11 of the first 12, struggled for grip during today's session and had to settle for fifth position.
Perhaps more significantly, the Mercedes driver was over a second slower than pole-sitter Sebastian Vettel.
Hamilton has finished just once off the podium this year, and the Briton reckons tomorrow might be difficult too.
"[Getting on the podium] is the goal," said Hamilton. "It's very hard to overtake, and the others, especially Red Bull, are really quick on the long runs.
"It is what it is; we'll find as hard as we can. I doubt we'll find something between now and tomorrow."
The world champion admitted he could not get his tyres working at all during the session.
"Tyres. I don't know really what we got wrong," said Hamilton.
"To be honest, it's exciting to have this kind of fight, it was the first time having to go into qualifying trying to pull even more [time] out of the car, and therefore sometimes making mistakes, so it was really challenging.
"But for some reason the tyres weren't working; you warm up the tyres like everyone else and then you finish your lap and you see someone else a second up the road."
Teammate Nico Rosberg qualified down in sixth and the German admitted he was baffled by Mercedes's lack of pace.
"Very frustrating; incredible that we're so far off the pace," he said. "Unbelievable. I can't remember when I was last 1.5s off the pace, it must have been years ago.
"It's incredible and we don't understand. For sure I was lacking a lot of grip, but who knows. If we knew what it was about, we would have solved it.
"I made set-up changes throughout the whole weekend in all different directions and big changes. I've gone full circle, I came back to what I started [the weekend] with in qualifying.
"Now we can't change anything so it's not going to help us tomorrow."