Kyle Larson to miss Martinsville after fainting at autograph session

Kyle Larson fainted at an autograph session Saturday and will not drive in Sunday's race at Martinsville. He's being replaced by Regan Smith.

Larson was awake and alert after the fainting spell and was evaluated at both a Martinsville-area medical center and a Charlotte hospital, where he was taken for evaluation by a neurologist. All tests so far have come back negative, however, according to the team, he's being held out as a precaution for more testing.

"After fainting yesterday at an autograph session in Martinsville, VA, Kyle Larson was first evaluated at a local hospital in Martinsville and ultimately evaluated at a Charlotte hospital," Chip Ganassi Racing said in a statement. "Although all tests came back negative and Larson feels completely fine, the doctors felt he should be held for more testing today. Subsequently, Larson will be unable to race today in the STP 500 in Martinsville."

Smith substituted for Kurt Busch earlier this season when Busch was suspended indefintely by NASCAR after allegations of domestic abuse. Smith drove three races in Busch's No. 41 car. He subbed for Tony Stewart in 2014 and has also substituted for Dale Earnhardt Jr. when Jr. missed time in 2012 because of a concussion.

Larson, 22, is in his second year in the Sprint Cup Series. In 45 career starts he has eight top-five finishes and 19 top-10 finishes. He's considered one of NASCAR's brightest up-and-coming talents and is a favorite to make the Chase in 2015. Since he's already attempted to qualify for Sunday's race, he is currently still Chase eligible.

If his absence extends through (or beyond) the Texas race on April 11, he would need a waiver from NASCAR to make the Chase. Given previous circumstances, the waiver is likely to be granted.

- - - - - - -

Nick Bromberg is the editor of From The Marbles on Yahoo Sports. Have a tip? Email him at or follow him on Twitter!