Rather than risk injury in Sprint Cup practice or in a Nationwide race, Denny Hamlin will confine his on-track activity to Friday's Cup qualifying and Saturday's Coke Zero 400.
Hamlin has been suffering from back problems this week after racing at bumpy Kentucky Speedway last Saturday night.
"There's a few things," Hamlin said of his back issues. "There's some torn discs, some bulging discs -- just a lot of different things that happened over time. It's just gotten progressively worse. Kentucky's not the smoothest of racetracks we've gone to with our progressive setups these days. Evidently it took its toll.
"The next day it just got real tight by the end of the day, and then I sat down for dinner and couldn't get up. I have a history of back spasms now for probably four years, and it just flared up again. This is about as bad as it was at its worst in 2008 or so. I'm just now starting to get mobile again and being able to get around."
Hamlin is an avid golfer and basketball player but said the back problems pre-date his involvement in those sports. He withdrew from Friday night's Subway Jalapeno 250 earlier this week and opted out of the two Cup practice sessions on Thursday.
Nevertheless, Hamlin won't have a relief driver standing by for Saturday's race.
"I don't plan on having a relief driver," Hamlin told the NASCAR Wire Service. "If something happened, and I didn't feel well, there'd be somebody around that could help, but I don't plan on having one. I could probably (practice) today, if I had to, but of course it's not race day, and I've got two more days before I really have to get in 'go.' "
Hamlin just signed a contract extension with Joe Gibbs Racing and said he has provisions in his contract that cover potential medical issues.
"As far as insuring a problem like this, we have stuff in place to help out when stuff like this happens," Hamlin said.