Dale Earnhardt Jr. had no idea how he would perform when he was asked to do some guest commentary during the 2016 NASCAR Monster Energy series.

At the time, the man voted 15 times as the Most Popular Driver had begun to contemplate retirement after suffering another serious concussion. Thoughts of what would come next in his life were swirling.

A transition to broadcasting seemed like a logical progression. He'd seen former drivers like Darrell Waltrip, Jeff Gordon, Kyle Petty and Jeff Burton do it, but Earnhardt, Jr. also knew he had no practical experience."

"I went into the booth to see if it was interesting to me," said Earnhardt, who retired from driving after the 2017 season due to another concussion.  "Would it be fun?

"I couldn't tell you if I was any good. I don't know if I'm a good judge of what a good broadcaster is."

Earnhardt said he was personally "elated" coming out of the booth for the races at Talladega and Martinsville, and then he got validation from fans, NASCAR insiders and television executives for the job he'd done.

NBC Sports was impressed enough by Earnhardt's potential that in July 2017 it hired him to join Burton, Rick Allen and Steve Letarte for the 2018 broadcast season.

On Sunday, he'll do color commentary in a dual booth with Letarte for the Gander Outdoors 400 at Pocono Raceway.

"It's been everything I hoped it would be and more in a lot of areas," Earnhardt said. "The entire NBC family has been awesome.

"I didn't know what to expect as far as the temperament and the whole groove around the race track. Everybody on the whole production team has been super nice.

"When you're a driver on the series, you've got to become a family. I was wondering if I could find that type of environment in anything else. It's there in the NBC production team."

Earnhardt, who says he studies for a broadcast the same way he would as a driver, has drawn earlier praise for presenting expert analysis with fun and flair.

His enthusiastic use of the dirt track phrase, "Slide Job," when describing Kyle Larson trying to pass Kyle Busch during the broadcast of the Overton's 400at Chicagoland Speedway immediately went viral on social media.

"I'm glad I kind of miss competing come race day," Earnhardt, 43, said. "If I didn't miss it at all, I'd be kind of freaked out by that.

"I miss it enough that it gives me excitement and energy to watch and get excited when something wild happens, that helps me in the booth to show what a fan of this I am. I think viewers enjoy seeing that."

The NASCAR broadcast contract called for NBC to take over from FOX Sports for the second half of the season.

Earnhardt did not get a six-month vacation.

NBC used him to assist with coverage at Super Bowl LII; the 2018 Winter Olympics in Peyoungchin, South Korea and the Stanley Cup Playoffs.

"I never imagined myself going to South Korea and covering the Olympics," said Earnhardt.  "I never thought I would be part of the pregame coverage for the Super Bowl.

"That's way beyond what expected from this, but if NBC says, "Hey, we could use you over here to help promote X, Y or Z," I'm a company man.

"When I raced cars, I did whatever I needed to do to help the company succeed. I'm going to do the same thing at NBC. I might be nervous, scared or apprehensive because of my inexperience, but I hope that over time I'll shake that off as I do more things and learn so that my confidence grows."