Jimmie Johnson on Rolex 24

Nerves hit Jimmie Johnson as he stood on the starting grid before the Rolex 24 at Daytona.

The seven-time NASCAR champion is entering a new chapter in his career – at age 45 – in unknown race cars. He was named to start America’s most prestigious sports car race for his Action Express team and Johnson had only one goal for his first stint in the Cadillac.

“Definitely didn’t want to break the toy in the first couple of hours,” Johnson said after driving about 70 minutes Saturday around Daytona International Speedway.

He gave up 48th place to his teammate Simon Pagenaud and then turned to Kamui Kobayashi, the reigning double Rolex 24 winner, for a lively debriefing.

Johnson, just over two months knocked out as the most dominant NASCAR driver of the past two decades, has “jumped to the bottom of the pool with weights on my ankles” as he moves on to new racing formulas. This Rolex 24 is the eighth of his career, but the first in a decade, and it’s a warm-up for his stint at IndyCar, where he’ll be a rookie in a field stacked with drivers half his age.

His career change has led to a busy off-season of testing alongside some of the world’s best drivers, and the demands have sparked a spark at Johnson. He was winless for the last three seasons of his NASCAR Cup career.

“I know the world I’m entering, and I know what I’ve moved away from and how comfortable I was there, and I’m very aware of my discomfort to enter this new arena, and that makes me feel alive, “Johnson said.” I’m so excited to be uncomfortable and so excited to learn something new, so excited to drive these cars and really grow as a driver and to have a bunch of new experiences in life.

“It makes me feel more alive than I have in a while.”

The Rolex started off with a healthy field of 50 cars, a strong rebound from 38 entries last season. Daytona officials said field attendance would be limited for the event, but did not release a capacity number. Campers were only allowed in motorhomes, with tents prohibited and masks required on the property.

Alegra Motorsports announced just before the start of the race that driver Michael de Quesada had tested positive for COVID-19 and had left the track to self-isolate. He was replaced in the Mercedes competing in the GT Daytona category by Mike Skeen.

Otherwise, the event went as planned. Halfway through the race was packed with fans visiting the manufacturers’ displays, the Ferris wheel was on and many of the world’s top road racers were eager to compete in the endurance event twice.

Johnson held his own in his first stint driving the Cadillac, and the entry of Action Express, partly with Hendrick Motorsports and sponsored by Ally, has a solid chance of securing the victory. His team will face the full-time entry of Action Express, which brought in defending NASCAR champion Chase Elliott on his sports car debut.

Hendrick sent a handful of his employees to Daytona, including former Johnson crew chief Chad Knaus and Jeff Gordon, who was part of Rolex’s 2017 winning squad for Wayne Taylor Racing. Johnson climbed to the top of the booth after his workout to chat with Elliott and Gordon.

Wayne Taylor Racing returned to Daytona as the winner of the last two Rolex 24s, as well as three of the last four dating from Gordon’s victory. But the team has gone from Cadillac to Acura during the offseason and still adapt to the movement. The transition was made easier by drivers Ricky Taylor, Helio Castroneves and Alexander Rossi, who have all driven the Acura for the past three years for Team Penske.

But the Cadillacs – there are four in the seven-car DPi class – have so far been the leaders of the field. Action Express’s entry with Elliott in the lineup came from pole after winning last weekend’s qualifying race, and Chip Ganassi Racing showed no signs of rusting after a year out of the series.

Ganassi’s entry was the overall race leader just over two hours after the start of the race, behind starter Renger van der Zande, who along with Kobayashi won back-to-back wins with WTR. Both seek to become the first driver to win three consecutive Rolex watches.

Ganassi, who has eight Rolex wins, also uses reigning IndyCar champion Scott Dixon and Kevin Magnussen, who switched to sports cars after seven seasons in Formula One.

As Dixon waited for his turn in the car, he marveled at the work Johnson has done over the past two months. Dixon and Johnson will be Ganassi’s IndyCar teammates.

“I think a lot of people, what they see, especially in our team, is just his work ethic and he crushes everything,” Dixon said. “He’s just trying to level up as quickly as possible. It probably has to be the most important job for anyone who’s ever tried to go from opposite ends of motorsport.”

Johnson admitted he was an old dog trying to learn new tricks.

“It was really fun getting behind the wheel in a whole new way,” said Johnson. “These high downforce cars, it’s just a lot of fun, number one, and just a huge challenge rewiring all the things I learned from driving the heavy sedans.”