Toro Rosso co-owner Gerhard Berger says Sebastien Bourdais must now prove he deserves a second year of Formula 1, having admitted that the team's 2009 driver line-up is currently "open".
Bourdais has been out-paced by team-mate Sebastian Vettel for the majority of his first F1 season, and with Vettel destined for the senior Red Bull team next year, Berger said it was now time for Bourdais to show his true capability and earn his seat for 2009.
The Austrian former grand prix winner admitted that Bourdais needed a period of acclimatisation having switched to F1 following a vastly-successful Champ Car career in America, but believes that he should now be fully up to speed - especially given how quickly Vettel got to grips with F1 in his own rookie season last year.
"In Formula 1 you have to give someone half a year of time before you start to judge him," Berger told the official F1 website.
"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."
Berger said the race for Vettel's vacant seat was also still wide open, although existing Red Bull-backed drivers were likely to be the main contenders.
"The first direction that we look in is obviously to the Red Bull young driver programme and then we’ll see," he said.
"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."
Toro Rosso has been linked to GP2 drivers Bruno Senna and Sebastien Buemi - the latter a Red Bull protege and already an RBR test driver - as well as Super Aguri refugees Anthony Davidson and Takuma Sato.
Berger added that whoever takes Vettel's drive had a hard act to follow.
"Sebastian has helped us a lot to get the right atmosphere back," he said.
"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."