Formula One champions Red Bull are more likely to promote their own young talent than try to lure Lewis Hamilton from McLaren if they have a vacancy at the end of the season, according to team boss Christian Horner.

Australian Mark Webber's contract with Red Bull, as team mate to 24-year-old double champion Sebastian Vettel, expires at the end of the year, as does 2008 world champion Hamilton's at McLaren.

The Briton was linked last season to Red Bull, with Formula One supremo Bernie Ecclestone suggesting only last month that Hamilton might want to move, but Horner told British reporters before this weekend's Australian season-opener that his team were unlikely to be interested.

"I think that it's difficult to envisage Lewis in our team," he said. "I think he's comfortable in the environment that he's in and we're certainly comfortable with the two drivers we have.

"We also took a decision to invest in youth and we've got two really exciting youngsters that are entering GP racing in Jean-Eric Vergne and Daniel Ricciardo - both very talented drivers and deserve that opportunity," said Horner.

"It will be fascinating to see how they evolve during the year. So we would be more likely to look inwardly than outwardly."

Both Vergne and Ricciardo are starting their first full seasons at Red Bull's sister team Toro Rosso with the potential reward of a promotion to partner Vettel should Webber retire or the champions decide a change is needed.

Germany's Vettel graduated in a similar way from Toro Rosso after winning the Italian Grand Prix in 2008.

"You've got to look at the balance within a team as well," said Horner, who recently tipped Hamilton's team mate Jenson Button, the 2009 champion, as likely to be Vettel's biggest threat from outside Red Bull.

"It's important to have the right balance within any team, not just with the drivers but throughout the organisation...our preference would probably be more to go with drivers in whom we have invested from a young age, and give them the opportunity to see how they evolve rather than take something external."

Horner refused to fuel any speculation about Webber's future however, saying the 35-year-old was in great shape, determined to bounce back from a disappointing 2011.

"I certainly don't think Mark is going into this year thinking this is his last," he said.

"He is motivated, he is hungry, he's enjoying Formula One again, he sees a future beyond the end of 2012. I think that inevitably when drivers get to a certain age...it's logical to take things one step at a time which is what both Mark and the team agreed to do.

"There is no pre-requisite that Mark won't be in the car in 2013. It's a long season. We'll talk about things at the end of the year."

Horner said there were no guarantees that youngsters like Frenchman Vergne or Australian Ricciardo would be ready to move up at the end of the year should Webber, who won just once last year against Vettel's 11 victories, decide to stop.

"It might take two years, or even three. It's just a healthy situation for the team to have two really young talented drivers who we'll be able to gauge against each other," he added.