Graham Rahal urges Alexander Rossi to build on Indianapolis 500 win

Rossi, who retains a Formula 1 reserve role with the Manor team he raced for last season, won the Indy 500 at the first attempt last Sunday via a fuel-mileaga gamble by his Andretti-Herta team.

Rahal was an IndyCar title contender last year and is in his 10th season at the top level of American single-seater racing.

He said Rossi has a responsibility to the series as the Indy 500 winner.

"It's not just what IndyCar can do - it's what Alex Rossi can do," Rahal said.

"That's what I said to him when I saw him - I said: 'You don't understand what just happened to you. This is your first time here. I get that.

"'But take this thing and run with it. You have to help this sport grow and your name can do that if you want it to.

"'Now if you don't and you disappear you can do that, too.'"

Though Rossi continues to attend F1 grands prix with Manor when his IndyCar schedule allows, Rahal reckons he now needs to turn his back on Europe.

"If Rossi is smart he has found a home," Rahal said.

"He can go pound around in the back of the F1 field for the rest of his life if he wants but the opportunity he has been given here is better than anything he is ever going to get.

"But that's his choice."

Rahal also wants IndyCar to exploit maximum benefit from the buzz surrounding the sellout 100th Indy 500 and Rossi's shock result.

"If I were every single one of these promoters I would be talking about the stars of the 100th Indianapolis 500," he said.

"If I were IndyCar I would be continuously talking about how great Indianapolis is and how great the crowd is.

"God knows, that is what NASCAR does even if it is true or not. That is what they do and people believe that.

"I would be out there constantly pushing that message.

"NASCAR has nothing on us. Look at the crowd at Indy - that's three Daytona 500s all in one place.

"I would be all over that all the time and continue to push the names and try to get out of the media anything we can.

"You have me, Alex, Josef Newgarden, Spencer Pigot, JR Hildebrand is in and out, Ryan Hunter-Reay is in his 30s and you have Sage Karam in and out and Conor Daly.

"There are quite a lot of American drivers here right now. If you go back in my Dad's day, were there really any more than that?

"I think the future is pretty bright. Everyone gets focused on American, American, American but the most popular winner of the Indianapolis 500 would have probably been Tony Kanaan of Brazil.

"It's not just an American thing in our series."