Dale Earnhardt Jr. will compete at Martinsville Speedway this weekend after being given the green light by doctors Tuesday. The popular driver missed the last two Sprint Cup races -- Charlotte and Kansas -- after being diagnosed with a concussion days after being part of a 25-car accident Oct. 7 at Talladega. That injury followed a concussion he sustained Aug. 29 at a Kansas event. Since his latest injury, Earnhardt has been evaluated by neurosurgeon Jerry Petty and other physicians, and Monday he drove 123 test laps in a Sprint Cup Series car at the half-mile Gresham Motorsports Park in Jefferson, Ga. Petty then cleared him after a final evaluation. \"Dale Jr. has done everything asked of him,\" Petty said in a statement. \"He hasn\'t had a headache since Oct. 12, and we have not been able to provoke any symptoms since that time. I have informed NASCAR and Hendrick Motorsports that he is medically cleared for all NASCAR-related activity.\" Having missed two races, Earnhardt is last in the Chase rankings, 122 points behind leader Brad Keselowski.