Horner won't favour Liuzzi

Horner is adamant that his previous relationship with Liuzzi - who won seven races and the F3000 championship for Horner's Arden International team in 2004 - will not lead him to favour the Italian over the other contender for the RBR seat, Austrian Christian Klien.

"I know Vitantonio very well and he's a talented driver," said Horner, speaking to the Reuters news agency. "But he'll be judged on what he does in an F1 car.

"We'll be looking at him and Christian Klien closely in forthcoming tests. We're in no rush to make a decision."

Red Bull has already signed both Liuzzi and Klien, with the intention being to put one of the duo alongside David Coulthard in the race team and keep the other as a test and reserve driver. Speculation had suggested that Klien was the leading candidate for the race drive as he already has a year's F1 racing experience with Jaguar, although Liuzzi's talent is highly rated - especially after his dominant run to the F3000 title.

The team has hinted that it may not finalise its driver line-up until the eve of the season-opening Australian Grand Prix in March.