Dale Earnhardt Jr. tells Marty Smith that after a few laps his nerves lessened during his recent test at Darlington, his first time in a racecar since missing the final 18 races of the 2016 season. (1:05)

Dale Earnhardt Jr. says he believes he is healthier now than he was before a crash at Michigan in June that caused a concussion, triggering balance and vision issues and nausea that kept him off the track for the final 18 races of 2016.

He feels so good that he plans to resume contract negotiations with Hendrick Motorsports before he returns to racing in late February, when the 2017 season opens at Daytona.

The 42-year-old driver's contract is up at the end of 2017, and negotiations with team owner Rick Hendrick were put on hold after Earnhardt stepped out of the car in July. Earnhardt, who in August decided not to return at all in 2016, tested Wednesday at Darlington Raceway and has been cleared to return to racing.

Dale Earnhardt Jr., now healthy after battling concussion issues, plans to resume contract negotiations with Hendrick Motorsports before he returns to racing in late February. Chris Trotman/Getty Images

"We're probably going to revisit that [contract extension] before the season starts," Earnhardt said Friday during a teleconference with reporters. "I've told you guys that before I got sick, me and Rick had been sitting down and talking about our future and the extension and what we wanted to do, and all that stuff was starting to come together.

"We're going to revisit that here shortly. That's definitely something on our list to get done."

Earnhardt spent the past five months doing exercises to help with his balance and reaction time, as well as his vision. He suffered from a lack of gaze stability -- the ability to move and remain focused at an object in the distance.

Dr. Micky Collins, of the University of Pittsburgh Medical Center Sports Medicine Concussion Program, oversaw Earnhardt's treatment. Collins also oversaw Earnhardt's treatment from a concussion in 2012, when he missed two races after two concussions over six weeks.

The hit at Michigan did not appear overly harsh, and Collins said earlier this year that the goal was to make Earnhardt able to handle such an accident without suffering concussion symptoms. Earnhardt said Friday he believes he's at that point.

"I wouldn't be coming back to the seat and wanting to drive and excited about driving cars if there was any risk other than the typical risk that every driver faces on Sunday," said Earnhardt, who also suffered two concussions early in his career. "I feel very confident in what I've seen in myself, my improvement and I feel confident in what my doctors tell me about my future."

Earnhardt said he does not expect he will have to undergo additional tests because of his concussion history if he gets into a crash, other than the evaluation given to any other driver.

"I have a personal responsibility to myself, to be smart, make great decisions for myself," Earnhardt said. "My health is No. 1. ... I'm not going to take any unnecessary risks with my own health."

The driver said beyond having a new helmet, he also has not changed any of his safety devices inside the race car.

"I feel real good about what we have [in the car]," he said. "I did get my head scanned for a new helmet, but that's just supposed to make it fit better, be more comfortable."

During the test Wednesday, Earnhardt would drive the car for 15-30 laps and then would be evaluated by his doctor during a 20-minute break. The test lasted about five hours, and Earnhardt said it helped him build his confidence.

"A lot of things he was checking -- visual and balance and so forth -- actually strengthened throughout the process [as] you sort of get acclimated and up to speed with what it takes to kind of drive a race car," Earnhardt said.

Hendrick said having Earnhardt out of the car "kind of deflates the place" -- and now that he is back ready to race, it has reinvigorated the organization. Earnhardt has 26 career Cup wins and has won NASCAR's most popular driver award for 14 consecutive years.

Earnhardt will test again Jan. 31-Feb. 1 at Phoenix International Raceway.

"I'm just glad to have had the opportunity to get so much time between [now] and the events I had last year and the symptoms," Earnhardt said.

"That's something that I think is really important for everyone going forward, is that they take the amount of time that they need not to just get symptom-free but to allow themselves to heal and get stronger. We still have a couple of more months of my brain being able to sturdy itself up [before racing again]."