Dale Earnhardt Jr.'s concussion symptoms will hold him out of a race car for the next two weeks. Earnhardt suffered the concussion during a wreck on July 2nd at Daytona where he was involved in a large accident.

"[My doctors] can give me a lot of exercises that retrain my brain to handle what I need to handle -- it's just going to take a lot of patience," Earnhardt said. "I take my health and quality of life as a top priority. ... I am going to take this slow and strictly take the advice of my doctors."

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Replacing Earnhardt Jr. will be 4-time champion Jeff Gordon who will be coming out of retirement months after his final race in the #24 Chevrolet for Hendrick Motorsports.

"I think Jeff will do well," Hendrick Motorsports owner Rick Hendrick said.

Gordon will race in the #88 car in this Sunday's race at Indianapolis Motor Speedway and next Sunday's race at Pocono Raceway. Gordon has five career Brickyard wins at Indianapolis, the most by any driver all-time.

"He's been out of the car this year. I expect if he gets in the car, he might be a little bit rusty, but we've got a lot of practice time and I don't think it'll take Gordon long to get back in the groove," Hendrick said.

Gordon spent the first 16 races of this season as a color analyst for FOX's NASCAR coverage.