"The goal has to be to do better than we have recently, which was Lewis's fifth place in Bahrain," said Rosberg.
"I'm sure we can do a bit better than Bahrain, but doubt we can fight for the win and the podium could be difficult."
Hamilton added: "I think for the race I am going to struggle generally. I have to look over things this evening and think how I am going to limit the tyre degradation, which is going to be a big problem for me.
"It's going to be real difficult tomorrow. I don't think it's going to be hugely different to the last race. We are doing everything we can and hopefully tomorrow will be a better day for us."