Toro Rosso team bosses Gerhard Berger and Franz Tost have travelled to Jerez to oversee the evaluation of drivers to replace Sebastian Vettel in 2009.

Ironically just days after 21-year-old Vettel recorded the Faenza based team's first win, they are weighing up a future without the German, as Sebastien Buemi drove the STR3 on Wednesday.

Out-of-work Japanese driver Takuma Sato, meanwhile, is scheduled to test on Thursday, and he spent his opening day at the Spanish venue in the Toro Rosso garage.

STR co-owner Berger told Germany's Auto Motor und Sport that the team will not make a decision about 2009 until November or December.

"The drivers that I can get today, will still be there in November," the former winner of ten grands prix said, possibly also referring to the fact that more drivers - including Nick Heidfeld, Rubens Barrichello and Nelson Piquet - might also be clearly on the market by then.

At Jerez on Wednesday, Vettel got a taste of life in a Renault-powered Red Bull, but his RB4 broke down with a gearbox problem.

Also notably, Williams gave the F1 world an early sign of the 2009 regulations, running one of the new higher and narrower rear wings.

Heidfeld will be in action for BMW-Sauber on Thursday, as Robert Kubica has called off his test with an infected tooth.

Source: GMM