Mark Webber reckons his team has a lot of work to do overnight after a disappointing showing in Friday's second practice.
Webber finished the afternoon at Valencia down in ninth place, 0.567s behind his team-mate Sebastian Vettel, after failing to get the most out of his soft Pirellis mid-way through the session.
"You get one lap - or two laps - on the option tyres, so we didn't do a good job on the soft at all," Webber said.
"So a frustrating finish to the session but we've got plenty to go through tonight.
"I think the car's working pretty well here, but Seb was on pole in Montreal and we finished fourth so qualifying's not what it's about - we've got to do well on Sundays."
Pressed as to what he thought of his race-pace, the Aussie said: "Not very good, but we know where we can improve.
"I think Seb had a reasonable long run but we know what we need to do to improve our long run pace... We need to improve. The option tyre wasn't great for me but we'll work on that tonight."
One of the aspects the Red Bull racer says will be discussed overnight is the Pirelli tyres, which he reckons will play a big role in the outcome of Sunday's European GP.
"Nothing's changed. We've got a lot of quick guys not where they should be and guys who have the tyres working in a good window and they're very quick as well. So it's all about those four corners, the black stuff on the corners of the cars."