A new Red Bull chassis didn't help Sergio Perez turn his fortunes around as he could only qualify in 13th place for the sprint race in Brazil.
The under-fire Red Bull driver continues to struggle for form after a poor performance in the US GP in Austin followed by his shocking home race in Mexico last weekend, where he finished 17th.
The pressure on Perez is ramping up, and again questions have resurfaced as to whether he will be retained by Red Bull next season, despite having a contract in place.
Perez was quizzed about his latest poor result and reeled off a list of excuses.
He said: "We had a good FP1 and then we had a little bit of understeer with the track [temperature] coming down.
"We tried to [deal with] it with the brake balance and the tools that are available and then I ended up a little bit too rear-limited.
"And then was a bit confusing on the programme. We thought we might have a chance for a second lap, and unfortunately, we didn't.
"Today we did struggle quite a bit and looking forward to tomorrow's qualifying, really. We got caught out with the conditions, unfortunately. And that really was the difficult bit."
Red Bull boss Christian Horner had earlier revealed the team had reverted to an old chassis to help boost Perez's confidence.
Horner again pledged his support for his driver but stopped short of providing a ringing endorsement.
He said: "We're doing our best to try and help rebuild his confidence. He had a horrible weekend in Mexico.
"We've changed his chassis this weekend. It's an older chassis, that we've put him into just to give him that extra boost of confidence.
"Sergio is a seasoned campaigner. He's been around long enough that he knows this is a results-based business.
"He knows that this season has been under-par for him. Nobody's more acutely aware of that than Sergio, but we're doing our best that we can to support him."
Meanwhile, team-mate Max Verstappen will line up on the second row after qualifying in fourth place for the sprint.
The world champion also criticised the bumpy track for not helping his cause.
He said: "As soon as we went into qualifying, it looked like we were definitely off the pace.
"The car was a bit difficult on the bumps. They did the resurfacing but they actually made it worse to drive. It's extremely bumpy everywhere, so that's not good for our cars.
"All the bumpy areas, the car is jumping around a lot, and it's costing me quite a bit of lap time.
"Normally when you're already quite a bit off over one lap, I don't think we are particularly strong in the race. So we'll have to see how that goes tomorrow in the sprint.
"I also know there's maybe some weather around that can come, but maybe not for the sprint."
