Sebastien Buemi has denied he has signed a contract to remain at Toro Rosso in 2011.
In a team-distributed interview on Thursday, boss Franz Tost said 21-year-old Swiss Buemi as well as Jaime Alguersuari are "both confirmed" for next year.
But Buemi told Blick newspaper: "I haven't signed yet.
"There are some details missing and the driver market is still open," he added.
At Silverstone last weekend, Renault chief Eric Boullier said Buemi "is on our list" of potential replacements for the Russian pay-driver Vitaly Petrov.
And Red Bull's driver consultant Helmut Marko said the energy drink company "might consider placing him (Buemi) in the Red Bull (Racing) team in 2012."