Mercedes swept Ferrari aside in qualifying, with Vettel's fastest lap eight-tenths down on Valtteri Bottas, who claimed his third consecutive pole position.
After Friday running, it was clear that Ferrari was missing out in the third sector, but Vettel says that it is not just the final sequence of corners where the Scuderia outfit is losing time to their rivals.
"We're slower in the corners, not just the last sector but the other sectors," he said. "We're faster on the straights by quite a chunk, maybe that will help us tomorrow to put pressure on early on, we'll see.
"It's a long race, and we seem to lack a little bit of overall grip to match their performance but we'll try everything we can tomorrow."
Vettel admitted that the gap on the timesheets surprised him, as Ferrari goes in search of its first win since the US Grand Prix last year.
"Yeah it did [surprise him]," Vettel said of the gap to Mercedes. "We would like to be closer but we're not. We tried a lot of things. We've been brave, exploring different directions.
"The parts that we brought, they seem to work and they're a step forward, but we're still behind so still a lot of work ahead of us.
"The favourites are Mercedes, they are a lot faster than us. We will see what we can do in the race. Otherwise, we'll just stop here and have a siesta tomorrow," Vettel joked.
"But our job is not to have a siesta so that other people can enjoy siestas so we'll fight as hard as we can and hopefully we can squeeze out more than we expect.
"I would say we'll race as hard as we can and see what we can get. We're not the favourites but we'll try to give them a very hard time."