Two of IndyCar’s biggest names, Romain Grosjean and Jimmie Johnson, have been given clearance to contest next year’s Indianapolis 500.

Despite the Rookie Orientation Program (ROP) being cut short due to rain, officials approved the pair should they enter the 106th running of the Greatest Spectacle in Racing.

The ROP is a prerequisite for all prospective Indianapolis 500 competitors.

The test requires drivers to complete 10 laps of the speedway between 205-210 mph, then 15 laps between 210-215 mph, and finally 15 laps over 215 mph.

For Grosjean, it marked the first time he has driven at speed on the oval-configured Indianapolis Motor Speedway.

“It went pretty well,” said Grosjean, who appeared for the first time in DHL colours with his new team, Andretti Autosport.

“It was a very smooth day, apart from the weather that was playing with us.

“I got some good explanation, some good tips from the guys, from the engineers also.

“James Hinchcliffe came in the morning, which I appreciated a lot. Michael [Andretti] was there, as well.

“When you’ve got those guys, they know what they’re talking about, so that was great to be with them and to know what to do.

“Then just going out there. I think really the most stressful part was to know what my first lap speed was going to be.

“You grow up or move from there. I had no idea what to expect to get to 205. Then it went pretty smoothly, enjoyed it. When you have to go above 215, that’s where the fun starts.”

Grosjean said it took some time to wrap his head around the programme, which requires drivers to slowly work their way up the speed charts.

The Frenchman leant on 2016 Indianapolis 500 pole-sitter Hinchcliffe for advice, taking note of the wind direction each lap.

“It was definitely an exercise, but I took it like I wanted to save fuel,” Grosjean said of the process.

“I didn’t lose time aiming for the speed, I was more aiming at how can I possibly save fuel in the race and look at that and get some early knowledge out of it.

“Honestly, it was pretty straightforward. Everyone told me 205 [mph], 210 [mph] is going to feel bad because the car will not be settled.

“I did feel pretty good, so I guess the set-up was pretty good.

Of the best advice he received, Grosjean commented, “I guess look at the windsock, that was a good one. You don’t think about it if you don’t know about it.

“Don’t go too low down the line, hit the inside curves. Pump your brake before you get to the pit stop.”

While it was the first time for Grosjean on the quad-oval, Johnson has had plenty of experience at Indianapolis, albeit in the NASCAR Cup Series.

Prior to his first IndyCar test, Johnson has made 18 competitive appearances in the Brickyard 400 with Hendrick Motorsports.

Johnson first won the race in 2006 and again in 2008, 2009, and most recently in 2012.

“[It was] just a special day to drive an IndyCar at the Indianapolis Motor Speedway,” said Johnson.

“I have truly, truly enjoyed it. It was a childhood dream come true. The experience is more than expected and something that I really, really enjoyed.

“Dodged some rain showers. Certainly didn’t run as many laps as I hoped to. In the crunch, felt like I got up to a great pace and had a good sense of the car around the track.”

Johnson was supported trackside by his Chip Ganassi Racing team-mates Marcus Ericsson and Tony Kanaan while Scott Dixon and Alex Palou were checking in via text from afar.

The team’s advisor Dario Franchitti, who has three Indianapolis 500 wins to his name, was on hand at the test.

“Dario flew across the pond to come be a part of it, Marcus Ericsson was there, Tony Kanaan, Dixon was texting in, Palou was on the simulator and texting in,” said Johnson.

“My CGR family was keeping a close eye on me, helping me get up to speed, which I think came in pretty easily, especially through these phases take place.”

Next year’s Indianapolis 500 is slated for May 29 (local time).