Minardi confirm Clarke, Doornbos

While Doornbos has already tested with the team, Clarke has been on the sidelines since the end of his promising rookie season.

"I've been waiting and hoping for this news for a few weeks now, and I'm relieved it has finally been confirmed," said Clarke.

"Although I haven't been in the new car yet, I've kept in close contact with the team and attended the tests, while also concentrating on maintaining peak fitness, so I'm as prepared as I can be at this stage without having driven the DP01."

Minardi boss Paul Stoddart formed his Champ Car operation by buying the HVM-CTE team, which Clarke had driven for in 2006, late last year.

Doornbos will continue his role as Red Bull's F1 test driver alongside his Champ Car programme.

"I'm really pleased to be racing with Paul Stoddart, Keith Wiggins and Minardi Team USA," said Doornbos. "It's obviously a different Minardi team from the one I last drove for, in Formula One, but there is still the same, close-knit, family feeling about it that I like."

Zsolt Baumgartner, another former Minardi F1 racer, has already been confirmed as the team's test and reserve driver.