Nico Rosberg says it could take several weeks for the Mercedes to be competitive in race conditions.
Despite strong qualifying performances, Rosberg and teammate Michael Schumacher have suffered from tire issues in the first two races of the season and the German expects Mercedes to struggle in China as well.
"The big problem is with the tires on this track, especially the front tires, they destroy very easily so you have to be very careful and find a set-up for the car to help that," said Rosberg.
"It is not so easy because in the race we are still having some difficulties, in qualifying we are very good and we will try very hard to improve but it will take some time.
"We can't expect to come here and all of a sudden win the race, it will take some weeks."
Team boss Ross Brawn said Mercedes is concentrating on improving performance for the race.
"Whilst our low fuel runs look good, our primary focus has been on race pace and working to understand the tires so that we can use them as well as possible on Sunday."
Schumacher set the pace in the afternoon session, with Rosberg down in fifth position.