LOUDON, N.H. – Dale Earnhardt Jr. has gone winless in 18 races this NASCAR season.  When he will compete in number 19 is now unknown.

He has dropped out of Sunday’s Cup race at the New Hampshire Motor Speedway due to symptoms of a concussion.

Earnhardt was evaluated in Charlotte, North Carolina, this week and doctors did not clear him to race. Hendrick Motorsports said on Thursday it had no timetable for his return.

Following this past Saturday’s race at Kentucky, Earnhardt recently met with a neurologist.   He claimed he was not feeling well.  Earnhardt was involved in a 22-car crash on July 3 at Daytona.