David Coulthard has admitted that he underperformed at McLaren-Mercedes the last two years or so, but only because he didn't feel wanted.

The Scot, who signed a one-year deal with Red Bull Racing on Friday, after a successful test at Jerez, added that he now hopes to re-invent himself at the former Ford owner team, in much the same way as Jenson Button re-vitalised his career after being thrown a life-line by BAR.

"Two years ago Jenson was told he was finished," Coulthard told British newspaper, The Sunday Mirror.

"But he went to BAR and was suddenly doing a good job. Now the team is behind him, look what he has been able to achieve.

"I could do that."

Coulthard, who struggled in 2004, and who was largely overshadowed by Kimi Raikkonen, was released, after team boss Ron Dennis signed Juan Montoya to partner the Finn, a decision that was oddly announced over a year ago.

"Obviously the last year and a bit have been a difficult period in my career but to perform you have got to be in the right environment," explained the Scot.

"I have not been in the same environment as my key competitors. They are secure, wanted and they are at different stages and different levels of the sport. Of course that influences you.

"If the psychological side wasn't important then team support systems wouldn't matter.

"In the circumstances, I believe I have done a reasonable job."

"The desire to do the job, to work hard and be professional is as strong as it's ever been," he added. "My work ethic is the same, although there have been days this year which have been disappointing.

"When you perform well it's great, but when you are not the spotlight falls on you and it's an unpleasant experience. You wouldn't want to go through it on a daily basis.

"There was a failing on my part last year when I couldn't deal with the one-lap qualifying.

"That's what forced McLaren to make the decision they did."