Getting used to a new team and a new car are challenges, but Magnussen is no stranger to pinch-hitting. In the past he has substituted for both Paul Tracy and Emerson Fittipaldi in CART champ car events when he was running in that series. He has also been one of the most highly-regarded 'subs' in racing during his years when he was a Formula 1 test driver, a role he performed for McLaren in the nineties before he landed a F1 ride with Jackie Stewart's team in 1997-1998.

Theys and Magnussen have never driven together and don't know each other well, but they are both looking forward to changing that at Homestead.

"He has one of the best reputations in the business," said Theys, a Belgium native who lives in Scottsdale, Ariz. "From Formula 1 to sports cars, he's driven everything. He is a very good sports car driver."

Much has been written about the recent changes made to the Homestead track. Theys hasn't seen it since then, let alone drive on it, so he's not sure what to expect.

"I've seen pictures of it, that's all," he said. "Before [the changes], going fast on the banks was a challenge, but now I heard it's not as challenging for the drivers," he said. "But I will confirm that to you after the race," he quickly and wisely added with a chuckle.