After final practice for Sunday's Kobalt Tools 500 at the Atlanta Motor Speedway, Martin Truex Jr. went to the emergency room for a kidney stone.
It is unknown whether he will be able to race.
Truex Jr., who will start 23rd in the event, waited until both practice sessions had been completed before heading to the hospital. It is believed that he will pass the stone tonight and be ready for Sunday's event.
However, if he doesn't, then he should still be able to race if he is able to deal with the pain. He won't be allowed to take any pain medication because it could be in violation of NASCAR's substance-abuse policy.
No word on who would be a replacement driver if Truex Jr. is unable to compete.
Source: Espn.com, Scenedaily.com