"It's been a very hard day", said Hamilton.
"We tried to prepare everything so we got the tyres on the vehicle, because we knew that roughly two minutes before the end of the session we have to go out", Vettel added.
"It's completely different tracks", Wolff said.
"There is a fundamental issue in the vehicle that we need to find out". Sky Bet make him odds-on to add another 25 points to his tally by taking the chequered flag, while he's also a 3/1 Price Boost (from 2/1) to win the race and set the fastest lap time. On Saturday morning Hamilton reverted to older parts while Bottas stuck with the upgrade in an attempt to offer a comparison and gain a better understanding of the problems ahead of qualifying.
"It's been a hard day but the guys were phenomenal fixing the vehicle, changing the engine in just two hours".
"Even if we got the greatest of deals - do it for free for example - what's the product?" "I didn't sleep very well, just like all my engineers as well, because we didn't know whether we would fix the issue or not".
Hamilton was only able to go fractionally quicker to slot into fifth, and both were demoted a position when Fernando Alonso put in an impressive lap to go a tenth faster and slot his McLaren-Honda into fifth behind Verstappen.
Raikkonen said: "Everything went smoothly, not too bad. I think we have a strong auto", Vettel said at a press conference ahead of Malaysia Grand Prix scheduled this weekend.
Questioned about Mercedes' apparent struggles, Vettel expressed both surprise and a degree of suspicion.
"It's a nice circuit", he continued, "but the only thing you see is the airport, the hotel next to the airport and the circuit".
Wolff, meanwhile, insisted Mercedes' struggles were real and they weren't saving their true pace for today.
He was gracious to his championship rival, and then proceeded to wish Verstappen a happy 20th birthday, asking interviewer Johnny Herbert, "Does he look that much younger than me?" "I don't know whether he feels pressure".
Speaking to Sky Sports television, Wolff said the team had struggled from the start and in both wet and dry conditions with a temperamental vehicle he has previously described as being a bit of a "diva".
Worryingly for Hamilton, the auto was struggling on both short runs with low fuel and longer runs with high fuel.