Sebastian Vettel has been offered an IndyCar test after suggesting Road America would be "thrilling" for F1 drivers to experience.
The four-time world champion retired from the inaugural Miami Grand Prix after contact with Mick Schumacher in the first of two United States-based races this year.
The race was added to capitalise on F1's market growth in the US but bypassed more historical circuits in the country, such as the Indianapolis Motor Speedway that hosted the United States Grand Prix in the 2000s.
Vettel made his F1 debut at IMS for BMW Sauber but with Miami and also Las Vegas being added to the calendar, he was asked if a circuit like the home of the Indy 500 could fit with the scheduling direction.
"I'm not sure I'm the right person to judge because obviously, there's always personal flavour," replied Vettel.
"I think the US has fantastic race circuits with incredible history. Obviously, creating a circuit here is a very different interest. So racing in the cities is exciting because people are already there.
"You don't need to excite the people, because in the first place, they are already close.
"But certainly from a racing or driving point of view, I think racing… I think Indianapolis is a bit of a half racetrack. If you're not racing on the oval, you're not doing the real thing."
Outlining a circuit he would want to see on the F1 calendar, Vettel added: "Going to Road America…. for certainly the money that was spent to build this could have easily, you know, brought the standard up in great places, like Road America.
"From a driving point of view, I think they would be a lot more thrilling. From a fan point of view. I think that's difficult for me to judge because the last time I sat on the grandstand to watch the race was in 2001.
"So, a long time ago, and yeah, every fan is different. So I guess it's more for the fans in a way to decide. But certainly, from a racing and driving thrill, I'd love to go to proper tracks."
Rahal offers IndyCar chance
After Vettel made the comments ahead of the Miami Grand Prix, IndyCar star Graham Rahal took to Twitter to offer the Aston Martin driver a chance to drive on of his cars.
Rahal said: "I’ll double down and say it, Seb if you ever want to test an IndyCar at Road America we will make it happen.
"Would be an honour to have you in our car!"
Rahal's father, team owner, Indy 500 winner and three-time champion Bobby followed up the tweet by adding: "Seb, it's a deal if you wish!".