Sebastien Bourdais has expressed his surprise at AJ Allmendinger's switch to NASCAR for 2007.
Allmendinger currently lies second in the Champ Car standings behind Bourdais, who was crowned champion for the third year running last weekend at Surfers Paradise.
The American will race in the Nextel Cup next year for Team Red Bull, and Bourdais is disappointed to have lost one of his main rivals.
"AJ going to NASCAR is a little bit of a surprise," said Bourdais. "But he's young, he's American, and also very important and interesting for NASCAR.
"It's too bad for us because he was a great member of the Champ Car family, and as an opponent we'll miss him next year because he was one who definitely gave us a run for our money and it was an exciting year with him."
Allmendinger switched teams during the middle of this season, moving from RuSPORT to Forsythe, where he immediately won three consecutive races to put himself in the title hunt.
However, team boss Gerry Forsythe was quoted in the American press as saying that he was unable to meet the salary demands of the driver's management.
Bourdais added: "I think he's been shopping around since RuSPORT and himself parted ways, and I think it was hard for him to decide where he wanted to go. But it's the right time for him to move if he had to do it, because he is not building a family yet or anything."
The Frenchman also said that while he had a mild interest in NASCAR, he is happy to remain in Champ Car and chase a fourth straight title in the final year of his current deal with Newman/Haas.
"I tried to see with Mark Martin if I could get a test in a Busch car or something, but nothing really came out of it. Given the opportunity, I would probably test the car and see what it was like.
"Right now I know what I've got and I love it. This has been fulfilling my dreams and right now I'm just going to have fun focusing on it."
Bourdais also hinted that he hopes to race in the Le Mans 24 Hours next year, although he does not know what he'll be driving.
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