Bourdais thought F1 chance had gone

The 29-year-old Frenchman has won four consecutive Champ Car titles but expected to be overlooked by F1 in favour of younger drivers.

"At the end of 2005 I thought if I made it to F1 now it would be a big surprise, and at the end of 2006 I thought it was over and I said so at the time," he said. "But a week after I said I thought it was over for me, the opportunity to test the Toro Rosso happened.

"The only real chance I had before was in 2002 with Arrows, but that went away. It's difficult to have more than one opportunity because a new generation of drivers comes along and you're lucky if you get another chance. I got lucky and I'm finally there after many years."

Bourdais believes that he was overlooked in previous seasons because the level of competition in Champ Car wasn't rated highly by those in F1.

"The general health of open wheel racing in the states while I was there was not helping. I could only enjoying my time winning races and championships and keep in my mind that maybe one day there would be something in F1.

"I wasn't putting a lot of thought into it, waiting to see if it was ever going to happen. I was concentrating on doing my job. But F1 is unpredictable and it's not up to you to decide whether you have an opportunity, you can only take the chance when it comes along."