F1's youngest driver, Sebastian Vettel, marked his 21st birthday on Friday with a cake in Toro Rosso's Silverstone pit garage.

The German rookie's real present, however, may have been the announced retirement of David Coulthard, as speculation hits top gear that Vettel is first in line to fill the Red Bull race Seat for 2009.

He acknowledged the rumours as he spoke to reporters at the British grand prix venue.

"All I can say is that we haven't spoken about that so far," Vettel said.

"Perhaps we will in the future, but so far we are only concentrating on this season," he added.

Vettel joked that moving to Red Bull, with whom he is already under direct contract, would be simpler than going elsewhere in the paddock.

"I know the boss so that should help!" he laughed.

When asked specifically if he would move to Red Bull if the opportunity presented itself, Vettel answered: "Why not?"

Source: GMM