Swiss teen to combine back-up role with GP2 campaign.

Sebastien Buemi has been promoted to act as official reserve driver for Red Bull Racing's Formula One team this season, following promising performances in both testing and the junior categories he contested last year.

The Swiss driver finished as runner-up in the 2007 F3 Euroseries - behind new Renault reserve Romain Grosjean - but also took in the A1GP, GP2 and World Series by Renault competitions in a varied year, achieving varied success across the board. He graduates full-time to GP2 this season, running with the recently-renamed Trust Team Arden after impressing the team on his outings as replacement for the injured Michael Ammermuller at rival ART in 2007.

With the German's star fading slightly - he is currently flying the national flag in A1GP after being 'demoted' to the World Series by Renault in 2007 - Buemi also takes Ammermuller's place as back-up to RBR's race regulars Mark Webber and David Coulthard.

Buemi's confirmation, which took place at Red Bull Racing's official launch in Jerez, also signals the end of rumours suggesting that Robert Doornbos may return to the line-up. The Dutchman is now expected to remain in Champ Car, where he has been linked to the seat vacated by Sebastien Bourdais at Newman/Haas/Lanigan racing. Doornbos won two races and finished as leading rookie in 2007 while running with Paul Stoddart's Minardi Team USA outfit.