Sergio Perez is expecting a tough race at Monza for Sauber as the team has struggled for speed on the straights.
Perez lines up 12th on the grid, four places behind team-mate Kamui Kobayashi, and is targeting points despite doubting that Sauber will have much of an advantage on tyre usage.
"We lose too much on the straights, far too much," Perez told AUTOSPORT. "Everyone is running low downforce and our low downforce is not so good.
"In the race, we will try to reverse the situation and Sunday is the most important day. The target is to be competitive.
"It will be tough to beat the competition by strategy because I think many will try the one stop."
Perez is confident that Sauber will be stronger at circuits with higher-speed corners later in the season.
He remains certain that the team can still contend for fifth in the constructors' championship despite Mercedes currently having a 32-point advantage.
"It [fifth in the constructors' championship] is very important so we will have to try and maximise the results here," said Perez. "It's another opportunity to do some good points.
"Tracks with high-speed corners, maybe Suzuka, will suit the car. And I think we can be more competitive in Singapore than here."