Haas driver Romain Grosjean is braced for a "long and painful" Russian Grand Prix after ending up 20th and last in a disastrous qualifying session.
Having struggled for pace all weekend, Grosjean was slowest in the opening segment in qualifying at Sochi, losing a chance to improve when yellow flags were shown for incidents involving Jolyon Palmer and Pascal Wehrlein.
But a despondent Grosjean doubted he could have progressed to Q2 even if he had managed his last lap.
He fears Sunday's race could be a laborious one from the back of the grid if Haas is not able to get to the bottom of his balance problems.
"Since yesterday morning I've been complaining about the car, something not suiting me, something not normal," said Grosjean, who will move up to 19th on the grid given Stoffel Vandoorne's penalties.
"Same thing in qualifying, so we haven't found what's going on.
"The performance is very poor.
"I got the yellow flag on a much faster lap, but I don't think it was good enough for Q2.
"That's where the car has been all weekend long, so I don't really know what's happening.
"First lap I go in one corner and I have massive oversteer, then second lap at the same corner I have a big lock-up and go straight - same braking phase, same map. Sometimes it goes straight on, sometimes sideways.
"We're investigating, but clearly something is not working.
"I'm hoping we find something tonight or tomorrow is going to be long and painful."
Haas team principal Gunther Steiner was sceptical about whether there was anything mechanically wrong with the car.
"I believe it when I see it," he said.
"We need to check it, obviously.
"You can never exclude anything but I think a lot of people out there are struggling with the front and rear tyres here.
"Sometimes you have a bad weekend where you cannot find the balance and these cars are very difficult to handle and ask [Lewis] Hamilton, he's half a second off [Valtteri] Bottas - I guess he's not a happy guy today and he doesn't know why."
Asked whether likely one-stop strategies would make progressing up the order difficult, Grosjean replied: "[The degradation] is very, very low. You could almost try doing all race on the ultra-soft. So that's going be tricky.
"On the other hand, you have very long straight lines, so when you are following another car and you open the DRS you gain a massive amount of top speed, 27km/h or something like that.
"That's positive, we can push on the tyres, which is good when you want to overtake.
"We just need to find some pace. Without pace there's nothing we can do."