Sebastian Vettel thinks Ferrari needs to improve on Saturday after admitting the team was too far from Mercedes following Friday practice for the Abu Dhabi Grand Prix.
Vettel was the quickest Ferrari driver in the second practice session, but he finished down in fifth position, over seven tenths of a second behind pace-setter Nico Rosberg in the Mercedes.
The German admitted he was surprised by the pace of the Force Indias, after Sergio Perez emerged as the closest challenger to the Mercedes duo.
"We have to improve. We are a little bit too far behind," said Vettel. "I would like the gap to be smaller and also the gap to be bigger compared to the cars behind.
"Force India was was surprisingly quick, also Red Bull, so there's a lot of work for us.
"It's Friday, so we went through our stuff and we are reasonably happy, and the rest we'll see tomorrow. I think we can improve the car so let's see."
Teammate Kimi Raikkonen was seventh fastest, and also conceded the speed of the Mercedes was a worry.
"I haven't seen the data from today yet, but it's only Friday and we don't know what the others were doing," Raikkonen said.
"Obviously there is always something that we can improve, the Mercedes seem to be very fast, but we'll try to do as good a job as we can tomorrow."