World champion Sebastian Vettel is refusing to let stories linking him with Ferrari and Mercedes affect him.

The obvious assumption in recent weeks in the wake of the 23-year-old becoming the youngest winner of the Formula One drivers’ title is that he will soon uproot from Red Bull and join one of the bigger boys.

Vettel has a contract for this season with Red Bull and an option for next season, which is relevant given Felipe Massa is in the last year of his deal with Ferrari and expected to be on his way if he fails to improve on last season’s showing.

That has heightened speculation linking him with the Italian marque, yet a significant question mark exists over whether Vettel would want to partner Fernando Alonso.

As for Mercedes, Michael Schumacher sparked that debate this week when he suggested the German manufacturer would be foolish if they did not show an interest in Vettel once he hangs up his helmet for a second time at the end of 2012.

On the day Red Bull unveiled their new car for this year, the RB7, Vettel dismissed the possibility of such rumours proving destabilising and psychologically unsettling.

‘‘It’s smart not to put too much store in those comments,’’ said the 23-year-old, who was quickest at the end of the first day of testing at Valencia’s Ricardo Tormo circuit.

‘‘In the off-season there is no wheel-turning, unfortunately, and there are still pages to be filled and stories to be written.

‘‘Sometimes you don’t understand, but then that’s the off-season.

‘‘I’ve said many times that I’m very happy with where I am, and I’m very comfortable within the team.

‘‘The focus now is on the new car, so I don’t want to think ahead too much.’’ Looking beyond the immediate future, Vettel added: ‘‘If you’re asked as to where you see yourself in five or 10 years then for all of us it’s a difficult question to answer.

‘‘Even if you look back five years then maybe you didn’t think you would be where you are now.’’ Red Bull advisor Helmut Marko, right-hand man to team owner and energy drinks magnate Dietrich Mateschitz, claimed recently there was a clause in Vettel’s contract.

Although Marko refused to expand, it has been suggested if Vettel finishes in a certain position in the championship and wins a certain number of grands prix, Red Bull can exercise the option in his contract for next year in their favour.

Team principal Christian Horner, who stonewalled the subject of the contract, is hoping if his team can continue to provide Vettel with a winning car he would not want to leave anyway.

‘‘It’s obvious that what Sebastian achieved last year is something quite remarkable,’’ said Horner.

‘‘He has developed tremendously well at such an early age and he has a very bright future ahead of him.

‘‘While we can provide him with a competitive car and he feels comfortable here, then I don’t see any reason why we shouldn’t continue for years to come.

‘‘We’ve a very strong team, and that goes from both drivers all the way through the organisation, and it’s all about the package, all about everything coming together.

‘‘That’s the strength of Red Bull, that together with the spirit that exists within the team, we continue to push and strive for further success.’’ That spirit will need to be in evidence between Vettel and team-mate Mark Webber after a contentious season last year that often boiled over between the two men.

Many feel Webber’s best chance of being champion has now gone, but the Australian was today in an upbeat mood ahead of the longest season in F1’s history, spanning 20 races.

‘‘Obviously it was very hard in the middle of a season, when we’re all achieving some pretty big things, as the team did last year, to tackle and learn about some of the things that went on,’’ said Webber.

‘‘But as a group we went through a huge amount last year, and we certainly all learned from that. I know I certainly did.

‘‘So the way I am approaching this year is head-on again. I’ve a great opportunity, and a great team around me, to try to improve on what I did last year.

‘‘There are a lot of things I did right last year, some very proud moments, with 80 per cent of my season in the middle good.

‘‘So it’s a case of trying to improve on those things, and go for it.’’