Red Bull owner Dietrich Mateschitz says Sebastien Buemi is very likely to be one of Toro Rosso's racing drivers next year.
The Faenza-based squad have both seats vacant for 2009 and have tested Buemi as well as Takuma Sato alongside Frenchman Sebastien Bourdais, who raced for the team in 2008.
Mateschitz said 20-year-old Swiss Buemi is the main candidate to land one of the seats.
The Austrian also claimed the final line-up would be announced before the end of the year.
"One will very likely be Buemi," Mateschitz told autosport.com. "The line-up will be confirmed before the last test in December."
The final test of the year at Jerez takes place on 15-17 December.