Ganassi NASCAR driver Larson cleared to return after health scare

The Ganassi driver fainted during an autograph session last Saturday, and spent the next two days in hospital undergoing tests.

Doctors confirmed that the 22-year-old had been suffering dehydration.

"It was just kind of a weird morning because I was almost late to practice, so I just rushed myself that morning and didn't take very good care of myself throughout the day and just ended up dehydrating myself," Larson said.

"Just got to do a better job of taking care of myself, and that should never happen again."

Regan Smith stepped in to cover for Larson at Martinsville, finishing 16th, and Larson said that his missing the race was more due to the litany of tests that he was subjected to rather than any concerns that he might faint again.

"I don't know if they kept me out because they thought I would faint again," he said.

"They wanted to make sure there was nothing serious wrong with me, so they took their time and pretty much ran every test possible to make sure I was OK.

"All the tests that I took, they took a lot of time. That's the main reason why I wasn't able to get there for Sunday's race; there was a lot of tests to be run."

NASCAR does not have a race scheduled for this weekend, meaning that Martinsville is the only race that Larson will miss as a result of the incident.