Dale Earnhardt Jr. will not compete in Sunday's NASCAR Sprint Cup Series race at New Hampshire Motor Speedway after experiencing concussion-like symptoms, his Hendrick Motorsports team announced Thursday.

In the release, the team said Earnhardt was evaluated this week in Charlotte and on Thursday was not cleared by physicians to race. Alex Bowman will be the team’s substitute driver this weekend at New Hampshire (1:30 p.m. ET on NBCSN).

“I wasn’t feeling great the week going into Kentucky (Speedway) and thought it was possibly severe allergies,” Earnhardt said. “I saw a family doctor and was given medication for allergies and a sinus infection. When that didn’t help, I decided to dig a little deeper. Because of my symptoms and my history with concussions, and after my recent wrecks at Michigan and Daytona, I reached out and met with a neurological specialist. After further evaluation, they felt it was best for me to sit out.

“I’m disappointed about missing New Hampshire this weekend. I’m looking forward to treatment with the goal of getting back in the race car when the doctors say I’m ready.”

A timetable for Earnhardt’s return is still unknown.

Bowman raced fulltime in the NASCAR Sprint Cup Series in 2014 and 2015, with a best finish of 13th at Daytona in July of 2014. He has competed in four NASCAR XFINITY Series races this season, all with Earnhardt's JR Motorsports race team.

This is the second time Earnhardt has pulled himself from competition for concussion-related issues. In 2012, he missed two races during the Chase for the NASCAR Sprint Cup after a wreck at Talladega Superspeedway.

“I’m proud of Dale for standing up,” said Rick Hendrick, owner of Hendrick Motorsports. “The number-one priority is his health, so we’re going to give him all the time he needs. We completely support the decision by the doctors and will be ready to go win races when he’s 100 percent. In the meantime, we have full confidence in (crew chief) Greg (Ives) and the team, and we know they’ll do a great job.”