Hamlin said he pulled something in his neck during the 22 laps that were run prior to a rain delay of nearly four hours. He was running fifth when the race was halted. The 18-year-old Jones, who has never competed in a Cup car, got in the JGR No. 11 car when the race resumed Sunday night.
"I just pulled something in my neck to upper back about lap 12," Hamlin said during the race telecast. "I started going backwards at that point. ... I stretched it out and we've been working on it the last few hours. I'm not 100 percent. With this format, it's all about winning, and there was no way I would have been able to go out there and compete for a win.
"It's just doing my team a complete injustice for me to go out there and run a bunch of laps. Instead, I think it's just better to have Erik come here and run some laps, get used to these Cup cars. We know where he is going to be in a few years."
The 18-year-old Jones earned his first career Xfinity Series victory last week at Texas Motor Speedway. He is expected to get some starts in the JGR No. 18 Sprint Cup car in place of the injured Kyle Busch before Busch returns sometime this summer.
"I don't know [when that will happen]. Obviously, this was far from planned," said Jones, who finished six laps down in 26th. "If I do, great. I'd love the opportunity to get a full weekend of practice and dial the car in for myself and be comfortable overall. I really feel like we can run top 15, top 10. ... We'll just have to see where it goes."
Jones had to restart at the rear of the field when the race resumed. Hamlin, who is already virtually guaranteed a spot in the Chase for the Sprint Cup with his win this year at Martinsville, will earn the points for where Jones finishes the race because Hamlin started the event.
Jones, who was at his home in the Charlotte, North Carolina, area and joked he was wondering when he would take a nap during the race, was flown to Bristol and got to the track just about five minutes before the race was restarted. He admitted he was uncomfortable in Hamlin's seat and his wheel position.
"I learned a ton," Jones said. "I wish I could start the night over and do it over again. It was an interesting situation, for sure. I never turned a lap until the green flag dropped. ... I had a like a 35-minute flight up, and that was the only time I had to reflect on what I was about to do. There were a few moments where I didn't feel nervous, but my stomach felt nervous."
Hamlin, who offered to continue racing, should be ready to get back in the car Friday at Richmond International Raceway, JGR owner Joe Gibbs said.
"You don't want somebody, an athlete like that, getting in a car like that," Gibbs said. "So as we talked it over, I just said, 'Hey, look, let's don't do this. Let's put Erik in there.' I think we made the right decision. Hopefully with that, we didn't aggravate anything else, so hopefully he gets some treatment, and then we'll be good to go next week."