INDIANAPOLIS -- NASCAR star Kyle Larson planned to remain at Indianapolis Motor Speedway and make his debut in a rain-delayed Indianapolis 500, rather than pulling out of the race early and flying to Charlotte for the Cup Series race there Sunday night.

Larson was attempting to become the fifth driver to do "The Double" by running the Indy 500 and Coca-Cola 600 in the same day. But that was thrown into doubt when a heavy storm hit the speedway. It lasted about an hour, and it was expected to take about two hours to dry the 2.5-mile track, putting an end to any hope Larson had of starting both races.

The last to do it was Kurt Busch in 2014, and the only driver to complete all 1,100 miles was Tony Stewart in 2001.

Larson said earlier in the day that the "priority" appeared to be staying in Indianapolis, but no decision had been made until the rain left the track. That's when a Hendrick Motorsports spokesman confirmed that Larson would remain at the speedway.

Justin Allgaier was on standby in Charlotte to run the No. 5 car in his place.

"It looks like it's going to be that window where I guess we might be able to get it dry to race today," Larson said earlier in the day, "but obviously that affects things for the 600. It's still the weather. You don't know how that is going to go exactly. But the worst-case scenario is happening, which is a bummer. We'll get on the track in something today."

Larson had hoped enough rain would force the Indy 500 to run Monday, allowing him to start both races.

Larson is starting fifth in the Indy 500 in the No. 17 car for Arrow McLaren in a joint venture with Hendrick Motorsports. That team's owner, Rick Hendrick, was at Indianapolis Motor Speedway earlier Sunday in hopes of watching Larson race.

With the start delayed by about four hours, Larson and his team were forced to make a difficult decision.

"It would be very tough," Hendrick had admitted during the week, when asked about pulling Larson from the Indy 500 early. "We've got a tremendous amount of folks there at Indy, and he's in such a good position. It would be extremely hard."

Larson had been planning to follow the blueprint used by others doing The Double: He would finish the Indy 500, take a helicopter to a nearby airfield, board a private jet to Charlotte, then climb into another helicopter for the last hop to Charlotte Motor Speedway. If the Indy 500 began on time, he would have just enough time to make it for the start.

"I've been around Kyle a little bit through my career," NASCAR driver Noah Gragson said. "He's a remarkable driver, and to be able to see one of our guys who we've raced with every weekend go and try a different discipline of motorsports is really cool."

NASCAR driver Chase Briscoe said he was excited to see Larson in the Indy 500 because of their shared background.

"I'm excited from the NASCAR side, but I'm more excited from the sprint car side, to see another sprint car guy go to the Indianapolis 500," Briscoe said. "It's kind of the origins of Indy. You had these sprint car guys who would go and run -- you had A.J. Foyt, Parnelli Jones, Jack Hewitt, Bryan Clauson recently -- and that was always the thing. If you were the best sprint car guy, you wanted to run the Indy 500. That was the dream. So it's cool from that standpoint."