Danica Patrick was already feeling the effects of a crash last Sunday at Phoenix when she took a shot to the head Thursday night.
Patrick was watching a dirt-track race in Las Vegas when a flying rock struck her in the head. Her boyfriend, fellow Sprint Cup driver Ricky Stenhouse Jr., owns a team that fields dirt cars.
"I feel like I got a concussion," Patrick said. "It's really sore. It hit me straight in the head, and I went to the ground. Good thing I had a hat on, or I feel there would have been blood."
Patrick told NASCAR officials that she was fine after the rock incident but that her neck was still sore after a head-on crash with an outside wall at Phoenix when a tire blew out on her car.
She said she doesn't expect to have any problems this weekend at Las Vegas in preparation for Sunday's Kobalt Tools 400.