Luca Filippi will make his IndyCar debut at Mid-Ohio this weekend with Bryan Herta Autosport, following on from his successful test with the team two days ago.
The Italian will replace Alex Tagliani, who has stood down from his seat by mutual agreement with the team as it works to reverse the poor results that have dogged it for much of the season.
Team owner Bryan Herta said that Filippi's feedback during his test convinced him that it was worth giving the 27-year-old an opportunity to race.
"Luca did a really good job during the test on Wednesday," Herta said. "We were very impressed with his quick adaptation to both a car and circuit that were completely new to him. We are all very excited to see how he does under race conditions."
Filippi said that he is looking forward to finally making his IndyCar debut after plans to run with Rahal Letterman Lanigan last year were thwarted by a last-minute sponsorship problem.
"I'm very grateful to BHA for this great opportunity because this is what I've been waiting for my whole life," he said.
"I'm really looking forward to the weekend. It was very good that we had an open test and I had a chance to work with the crew and engineers. I think we worked well together and they really looked after me.
"I like the Mid-Ohio circuit and the drivability of the car. I had a lot of fun at the test and we still have more time today to make improvements to get ready for tomorrow.
"Obviously I'm a rookie but I'm a racer and I'm competitive. I really want to do well and show that even though I have a different background, I can prove my abilities."
Filippi is best-known for his long and successful GP2 career, although he is also a race-winner in Auto GP and was a Honda Formula 1 test driver in 2008.