Team USA will give JR Hildebrand his A1GP race debut at Brands Hatch next weekend, in place of Marco Andretti.
Andretti has raced for the team since the second round of the year, alongside his IndyCar campaign in America, but will sit out the British event which takes place just three days before the first practice session for the Indianapolis 500.
Hildebrand is also racing in America this season, in IndyCar's feeder series Indy Lights and won at Long Beach last weekend. He has also taken part in the A1GP rookie sessions in Malaysia, New Zealand and South Africa this year.
"I'm really looking forward to the opportunity to drive for A1 Team USA and Andretti-Green next weekend at Brands Hatch," said Hildebrand.
"Marco and the guys have done a good job learning more and more about what we need, and I hope to make the most of all their hard work.
"I've really enjoyed driving in the rookie sessions at the other A1GP rounds I've attended and am excited to be able to take the car all the way through the weekend."