Sergio Perez believes a strong result will be almost impossible in the United States Grand Prix after running well off the pace in qualifying.
The Sauber driver was left baffled about why his team struggled for single-lap pace, after practice had pointed to it being able to extract some good speed from the C31.
With no answers as to why the scenario unfolded the way it did, Perez does not believe he can put on a repeat of the fightbacks that led to podium finishes from similar situations in Canada and Italy.
"I don't see this charge through the field really happening, but you are always a bit pessimistic when things don't go right," he told AUTOSPORT.
"But we might have a nice surprise like we have had in the past. Hopefully we can have it."
Perez will start 15th, one place ahead of his team-mate Kamui Kobayashi.
He ruled out a fundamental error in set-up as the reason for his eighth-row starting spot, and suspects that tyre management was the primary reason for it.
"We went in the wrong direction with the track," he said. "We did not maximise our potential, as we could easily have been in the top 10.
"With a very good lap [on Friday] we were able to go into the top eight, but we were not even close to it.
"We are trying to understand what went wrong, as at the moment we believe our tyre preparation was not the right one. The track conditions changed quite a lot for us."