AVONDALE, Ariz. -- Dale Earnhardt Jr. walked into the Phoenix Raceway garage about 30 minutes prior to the start of testing. There used to be days where he might not arrive that early for a monotonous test.

Earnhardt now values his time in a race car as he prepares to mount a comeback in 2017 after missing half the 2016 season because of a concussion.

He tested on Dec. 7 at Darlington Raceway to earn approval to return to racing in the Daytona 500 qualifying races Feb. 23. Tuesday was the Hendrick Motorsports driver's first time in a NASCAR Cup car since on the first day of a two-day test at Phoenix Raceway where each race organization could field one car.

"I was texting the guys [last night], 'Man, I don't know why, I'm just freakin' pumped up about this,'" Earnhardt said during the lunch break Tuesday.

After missing half of the 2016 NASCAR season due to a concussion, Dale Earnhardt Jr. is all revved up for his return to racing in 2017. AP Photo/Nick Wass

The 42-year-old Earnhardt was the first among the 13 drivers on the track but a small brake fire then sidelined him for an hour. With a new aerodynamic package this year that includes a smaller spoiler and less surface area of the front splitter, his team had a list of items for Earnhardt to test. Earnhardt didn't need to know all the changes; in order to give good feedback, he preferred to not have any preconceived notions of what the car might do.

"You miss the camaraderie and the friendships I have with my road crew," said Earnhardt, whose last race was July 9 at Kentucky. "I think they miss me. So that makes you feel good. They seem excited that we're working together and we're back together."

Earnhardt was happy with his speed in that was comparable to other drivers who have run strong at Phoenix, but it would be hard to know how he compared as there is no technical inspection and teams might have their cars set up to experiment during the test at the 1-mile track. He was fifth on speed in the first practice session. He indicated he felt fine, having recovered from balance and gaze stability issues that affected him for several months after the accident June 12 at Michigan.

"It's been a fun day," Earnhardt said. "It didn't really take any time to get acclimated or adjusted to anything. There's a couple of small new things with the cockpit or the dash, little things like that to get used to.

"This sport, it's funny how things continue to change, technology in the cars continue to change. As far as driving the car, I felt real comfortable out there."

The Hendrick No. 88 team nearly won the race at Phoenix in November with substitute driver Alex Bowman, who sat on the pole and then crashed with Matt Kenseth battling for the lead on a late restart.

"They're confident in themselves," Earnhardt said about his team. "For me, confidence is a big, big part of it. The fact that the team doesn't have any lack of confidence in what they're doing and where they are is a good thing.

"That's out of the way. I just have to build my own confidence in myself and feel like me and the car are working together as one unit."

As far as his expectations for the upcoming season, Earnhardt wouldn't mention specific goals.

"I'm just a little nervous if there will be any kind of learning curve but I don't know," Earnhardt said. "I hope there ain't. Sometimes you see guys in sport, no matter the type of sport, that are away for a while have to adjust to how much has changed since they have taken time off.

"Then there are some guys that have come back like they've never missed a day. I hope there's no rust to shake off. I'm really anxious to kind of get back there and have some success, go out there and run well and check that box that I'm right where we need to be."