Dale Earnhardt Jr. will miss the next two Chase for the Sprint Cup races after he suffered a concussion in the massive wreck earlier this week at Talladega, effectively ending his chances to take home the championship.  

The concussion, sustained during the 25-car, last-lap crash at Talladega Superspeedway, is Earnhardt’s second of the 2012 Sprint Cup season. The first, suffered Aug. 29 at Kansas, went undiagnosed until Earnhardt was checked out by doctors Wednesday, the Associated Press reported.

"I knew having those two concussions back to back was not a good thing," the popular NASCAR driver said Thursday to the AP. “I knew to go see someone whether I wanted to get out of the car or not.”

Earnhardt’s No. 88 Chevrolet will be driven by Regan Smith, according to Earnhardt’s team, Hendrick Motorsports.

The popular NASCAR driver and son of late NASCAR great Dale Earnhardt, Earnhardt Jr. will miss Saturday’s Chase race at Charlotte and the Oct. 21 race at Kansas.

Earnhardt is in 11th in the standings out of 12 drivers in the Chase, 51 points behind leader Brad Keselowski. With Earnhardt missing two races, he effectively has no chance to win the championship.

Earnhardt told the AP that he knew he had a medical issue after the Kansas wreck back in August but declined to see a doctor because he was “too stubborn.”

"With the Chase coming up, if I was to volunteer myself for medical attention, I didn't know how difficult it would be to get back in. I knew something was not right. But I decided to just push through. I'd had concussions before."

Earnhardt was enraged immediately after the massive wreck at Talladega Sunday, calling racing fans “bloodthirsty” after being told by reporters they enjoyed watching the crash and threatening to quit NASCAR if it continues to hold races at Talladega and Daytona.

"I regret making a bit of a scene and not considering the fact we're going to be in a totally different race car for 2013," the NASCAR driver told SBNation.com. "It's probably going to present a totally different style of racing at those tracks, so I probably have a bit more of a positive outlook on the potential for that style of racing to be really good with the next car.”

While Earnhardt will be sidelined for two races, an MRI taken Wednesday showed no damage to his head, Dr. Jerry Petty told the AP. It’s still unclear when he will next ride the No. 88 Chevrolet.

"He had no amnesia after either incident, which is very important," Petty said. We'll want to give him four, five days without a headache," and then they'll try to invoke a headache to see how he reacts before clearing him to race."