Grosjean braced for "long and painful" Sochi race

Having struggled for pace all weekend, the Haas driver ended up slowest in Q1 in Sochi, losing a chance to improve when yellow flags were shown for incidents involving Jolyon Palmer and Pascal Wehrlein.

However, a despondent Grosjean said he didn't believe the lap he lost as a result would have been good enough to progress to Q2, as he continued to battle chronic balance issues.

He added he fears Sunday's race could be a laborious one from the back row of the grid if Haas isn't able to get to the bottom of what was causing his issues.

"Since yesterday morning I've been complaining about the car, something not suiting me, something not normal," said Grosjean. "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."

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 ultrasoft. 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, 27 km/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."

Car problem "difficult to believe" for Steiner

Asked about Grosjean's woes, Haas team boss Gunther Steiner was reluctant to pin the blame on a problem with the car, as Kevin Magnussen didn't suffer similar issues in the sister car.

"I believe it when I see it, we need to check it obviously," said Steiner. "You can never exclude anything, but I think a lot of people are struggling with the front and rear tyres here.

"I don’t want to jump to conclusions and say something is wrong. The other car can do pretty good, so if there is something mechanically wrong it is difficult for me to believe it. But can it be the case? Of course, you cannot exclude it. We need to check.

"Sometimes you have a bad weekend where you cannot find the balance and these cars are very difficult to handle."

Additional reporting by Oleg Karpov