Kyle Larson will miss Sunday’s STP 500 at Martinsville Speedway after fainting during an autograph session Saturday afternoon.
The driver of the No. 42 Chip Ganassi Racing with Felix Sabates Chevrolet was initially sent to a local Martinsville hospital, but later was transported to Carolinas Medical Center in Charlotte, N.C., to see a neurologist.
"Although all tests came back negative and Larson feels completely fine, the doctors felt he should be held for more testing today," the team said in a statement released Sunday morning.
As a result, Regan Smith will drive the No. 42 Chevrolet in Sunday’s race at Martinsville Speedway.
Smith, a fellow Chevrolet driver, has three Sprint Cup Series starts already in 2015. The XFINITY Series regular filled in for Kurt Busch while he served a suspension from NASCAR. Smith finished 16th in the season-opening Daytona 500, was 17th at Atlanta Motor Speedway and finished 16th at Las Vegas Motor Speedway.
Smith has nine previous Sprint Cup Series starts at Martinsville, with a best finish of 13th in 2011.