By alley - Jul 22, 2016, 1:20 PM ET

NASCAR: Earnhardt sensing improvement

Dale Earnhardt Jr. says that he is beginning to feel improvements in the concussion-like symptoms that have temporarily sidelined him from the No.88 Hendrick Motorsports Chevrolet.

The update came via Earnhardt's Twitter account on Friday morning: "Today is the 1st day in many that I sensed improvement. Seen small gains during my physical therapy as well. Light at the end of the tunnel."

Earnhardt was forced to sit out last weekend's race at New Hampshire after seeing a doctor for symptoms including nausea and loss of balance. He was not given clearance to race, and no timetable has been laid out for his return. Jeff Gordon will

race the car

in his absence.

Hendrick said Earnhardt made an appearance at the team shop in Concord, North Carolina and showe -off the progress he had made over the past few days.

"Wednesday he came by the shop, and we got to visit," Hendrick said. "He looks good. He is encouraged. He is following the doctor's orders. We're really excited. He is in great spirits. He wants to get back in the car. He wants to race, but he also knows that the regime they have him on will get him right for a long time.

"So he's following those orders, but I can tell he is getting antsy. But he is going to do what they say. He's doing well."

Earnhardt first visited doctors prior to the race at Kentucky two weeks ago seeking treatment for what he believed was a severe sinus infection. But his doctors eventually concluded that issues pertaining to balance and nausea were likely the result of crashes in several races last month.

Thus, he was not cleared to compete.

JR Motorsports part-timer Alex Bowman drove the No. 88 at New Hampshire and Gordon will give the team a chance to compete over the next two races. But the most important focus, according to Hendrick, is that Earnhardt continues to improve.

Hendrick said his driver seemed "sharp" on Wednesday, but also admitted that the condition has temporarily shelved any talks of the two working out a contract extension beyond the one that ends in 2017.

"Dale and I talked earlier about multiple years beyond next year and I was involved when he went to the doctor," Hendrick said. "And then the doctors really took over and then we text back and forth, and then I got to see him face-to-face. I care about him as a friend and someone that means a lot to me and I want him to be healthy and right when he gets in the car and the doctors are going to dictate that."