The Hinwil-based team has struggled with the rear end stability of the C32 since the start of the season, and much of the development focus has been on improving that area of the car.
Tom McCullough, Sauber's head of track engineering, said there was the chance that the changes would be enough to allow Nico Hulkenberg and Esteban Gutierrez to both fight for places in the top ten.
"We have some further aero updates, including a modified rear wing, and we will be evaluating these during Friday practice," he said.
"Qualifying is particularly important here as overtaking can be difficult in the race. Our target for the race is to finish with both cars in the points."