Berger says Vettel will be missed

The young German joined Toro Rosso last year and has made quite an impression in the team, but Vettel will move to the sister team next year to partner Mark Webber.

Berger admitted Vettel has done a lot for the team and that he will be missed by everyone.

"Sebastian has helped us a lot to get the right atmosphere back," Berger told the official Formula One website.

"We had been really struggling with Scott Speed and Tonio Liuzzi last year, but he has proved what the team is able to do and has done it in a very nice way, with us, with the engineers, with everybody.

"That has pushed us such an immense step forward - it is really a pity to lose him. There is not a single soul in the team that is not sad to see him go at the end of the season.

"On the other hand we get so much from Red Bull. Without Red Bull, Toro Rosso would be nowhere, so it feels good that we can give something back, even if I would like to have him stay with the team."

Berger said the team were not ready yet to decide on their driver line-up for next season, although he made it clear they will look at Red Bull-backed drivers first.

"The first direction that we look in is obviously to the Red Bull young driver programme and then we'll see," he added. "But we are not quite ready yet.

"We don't really have a list in our heads at this stage. We are far from saying it's this one or that one because we are also waiting to see if something happens elsewhere - and probably then we'll get a new chance."

Berger also said that he had not yet formed an opinion on Sebastien Bourdais following the Frenchman's first half of the season, and insisted the Champ Car champion's future is yet to be determined.

"In Formula One you have to give someone half a year of time before you start to judge him," Berger said. "The half year is over and he is now in a situation where he has to prove his talents.

"I would not say that I already have a clear opinion on him, but I also have to say that Sebastian Vettel started a couple of races before and he performed very well in the first half year.

"So we will have to see how the second half goes for Sebastien Bourdais. And honestly I don't want to be drawn into an expression of opinion at this very moment."