Italian GP: Red Bull drivers struggling with one-lap pace at Monza

Webber's ninth place in the morning was the team's only top-10 result of the day.

The team also struggled for qualifying pace at Spa.

Although Vettel and Webber were happier with the car's performance on heavy fuel, they are hoping for improvements in qualifying trim.

"We are working hard, but not quite there yet," said Webber.

"We were a little bit more competive on the long run when we have got a bit of fuel in but we have got a bit of work to do with the fuel out.

"We are not normally Friday world champions but we have a bit of work to do tomorrow."

Vettel added: "I think overall we are not as quick as we would like to be, still some work to do I would guess."

The reigning champion was less certain about the car's race pace.

"I don't know what [Webber] did or the others did, but I think we are probably more competitive in race trim," said Vettel.

"But for sure today wasn't as good as we wanted our true pace to be, so you can see there is a lot to do.

"So far we ran through our programme and didn't have any problems. There is a lot to go through and learn from."