CONCORD, N.C. – Dale Earnhardt Jr. will not compete in the upcoming NASCAR Sprint Cup Series events at Charlotte Motor Speedway and Kansas Speedway after being diagnosed with a concussion following the Oct. 7 race at Talladega, Ala.

Earnhardt, driver of the No. 88 Chevrolets for Hendrick Motorsports, was diagnosed Wednesday afternoon in Charlotte. Regan Smith will be the team’s substitute driver at Charlotte and Kansas.