Gordon went just 11 laps Saturday before he told his crew he couldn't continue. He left out of a side door of his hauler and was escorted out of the track to get treatment. Crew chief Alan Gustafson said the team would not run the car in the final practice session and instead will get it ready for Sunday's race.
"I've had some spasms in the past, but this one, it was a little bit different," said the 42-year-old Gordon. "And so I just want to really be cautious and take care of it. It doesn't do me any good to be in the car right now."
Gustafson said the plan was for Gordon to start the longest event in NASCAR. Should the pain be too much, then Smith would take over the Hendrick Motorsports car.
Gustafson said Gordon felt back pain after qualifying Thursday night and had hoped things would improve before Saturday's practice sessions. But "after the first run, we talked about it and it was pretty detrimental to him physically to continue," Gustafson said.
Gordon said on Twitter he planned to rest and "be ready for 600 miles 2moro."
The four-time series champion is having one of the steadiest starts of his career with eight top-10 finishes in the first 11 races. Gordon moved into the points lead following a second-place finish at Texas Motor Speedway in early April and he's stayed out front ever since. He cemented his place in the Sprint Cup's championship Chase two weeks ago with a victory at Kansas Speedway.
Gordon will start 27th and hope his back holds out for 400 laps around the 1.5-mile race track.
"Luckily, we had a good 11 laps there and we've got our teammates and information that we're going to be able to gather from them," Gordon said. "It's all coming together very fast right now."
Gordon has had back spasms in the past and even considered retiring because of the severe pain. Regular treatment has kept the pain mostly in check and Gustafson hopes that will be the case again for Sunday.
Doctors "will get him in the best condition he can and get him ready to run tomorrow," Gustafson said.
This week's race marks the 20th anniversary of Gordon's first Sprint Cup victory. His crew chief then, Ray Evernham, said Gordon is much tougher than some believe and has raced through illness and pain before.
"We won the Southern 500 (at Darlington) when he started throwing up halfway" through the race, said Evernham, currently working for Hendrick Motorsports.
Evernham said Gordon believes his car is ready and is being smart by not hurting himself further by practicing.
"He'll do everything he needs to do to get to feeling good and I know him and tomorrow night in that car, he may need some help getting out of it, but when he's in it, he's going to be at 100 percent," Evernham said.