Sergio Perez believes that Sauber's best chance of beating Mercedes in the constructors' championship is a wet Brazilian Grand Prix.
Sauber is 12 points behind Mercedes, but with the German marquee not having scored a point in the last five races, it could get ahead provided at least one car makes it into the top six on Sunday.
But despite it being a tough task, Perez has not given up on scoring enough points to beat Mercedes.
"Rain might help us," said Perez when asked by AUTOSPORT about the possibility of rain. "Then anything can happen in the race.
"With a normal race, it will be more difficult. [It will be] very difficult, I would say, to get big points
"If we have a good weekend, everything can happen. Let's get out there and do the best we can."
The Mexican, who leaves for McLaren next year, is hopeful that he can end two years with Sauber with a strong result.
He has finished on the podium three times this year, but since finishing 10th in Singapore he has failed to score a point in five starts, something he denies is linked to his McLaren deal.
"It has been a good two years [with Sauber]," said Perez.
"They have been two successful years and I want to end my Sauber career with the very best result.
"We had a farewell dinner with my car crew [last night]. It's the last race for everyone and I wanted to thank my guys for all of their effort.
"We have had an incredible season and hopefully we can end it on a high.