CHARLOTTE, N.C. -- Sprint Cup driver Denny Hamlin suffered a compression fracture of his lower back in a last-lap crash involving former Joe Gibbs Racing teammate Joey Logano on Sunday at Auto Club Speedway.
Hamlin spent the night at a local hospital in the Fontana, Calif., area and was released on Monday to fly home to Charlotte, where Dr. Jerry Petty of Carolina Neurosurgery & Spine Associates will evaluate him later in the week.
Hamlin told reporters that it is too hard to say if he will be ready for the next Sprint Cup race as he walked out under his own power, according to one of his representatives.
Hamlin was wearing a back brace when he walked out of Loma Linda University Medical Center, according to USA Today Sports, which also stated Hamlin had difficulty breathing when talking to the reporters.
"The position I was in, I couldn't breathe at all," Hamlin said, according to USA Today Sports. "I'm still having a hard time breathing. Literally, when I felt a pop, I couldn't move at all and I knew I had to get flat to my back to be able to breathe again. That's why I rushed out and just laid flat on the ground to start breathing again."
Hamlin will meet with Dr. Petty on Wednesday or Thursday, according to the report.
"He's going to spend tomorrow looking at scans to distinguish what the next step is," Hamlin said. "We're kind of leaving the analyzing for him on what to do either surgery-wise or just stick with a brace and let it heal itself. Either way, obviously, both of them take a lot of time."
"I don't want to make it worse," Hamlin added. "It's not worth that."
The Sprint Cup series has this weekend off, then resumes its schedule on April 7 at Martinsville Speedway.
When contacted by ESPN.com, Dr. Petty declined to talk about Hamlin's case or compression fractures in general until he has met with Hamlin.
Dr. Joseph Estwanik of Metrolina Orthopedic & Sports Medicine Clinic in Charlotte said that without knowing the severity of the fracture, it is impossible to give a fair evaluation of whether Hamlin will miss any races.
"It could range from tough it out and get going what you can with minor injuries to, as you would expect, surgery," said Estwanik, the chairman of the Sports Medicine Committee for USA Boxing in 1992. "It's not appropriate to give a plan of action."
Estwanik said competing on pain medication in motorsports wouldn't be an option because "on pain medication, you can't even drive out of the driveway appropriately. It can not only affect the brain, but reflexes and timing."
Estwanik said he has worked with NASCAR drivers with back issues in the past.
"There are things that can be done ... getting braces, padding and the arrangement for the seat to assist [in reducing pain and discomfort]," he said.
But, he reiterated, without knowing the percentage of compression and other details, it is impossible to evaluate Hamlin's situation.
Hamlin, who is 10th in points after five races, wrote on Twitter: "I just want to go home."
He later tweeted "all good" with a picture of him wearing a brace.
Compression fractures of the spine typically are caused by a sudden, forceful injury.
Hamlin's car hit the inside retaining wall head-on after being spun by Logano on the final lap. Hamlin's car hit a small portion of the track where the SAFER barriers designed to reduce impact did not cover the concrete wall.
Hamlin climbed out of his car and immediately collapsed. He was carried off on a stretcher and then airlifted to a nearby hospital.
Symptoms of a compression fracture are severe pain in the back, legs and arms. Some might feel weakness or numbness in these areas if the fracture injures the nerves of the spine.
Hamlin has a history of back injuries. He sat out the Nationwide Series race at Daytona International Speedway last season due to back spasms triggered from an incident at Kentucky. He told reporters then he had bulging disks in his back.
Hamlin said then he and his doctors changed his training routine to include strength-building exercises for his back. He also cut back on golf and basketball.
He did not miss the Sprint Cup race.
"With spasms … anything can set it off," Hamlin said at the time. "Obviously, the most risk of having an accident in practice would be on a superspeedway. The likelihood of me getting in an accident in the Nationwide race would be high, as well.
"Those are all things that would trigger going backward from everything I've gained this week. So that's the reason. … Just wanted to minimize risk, that's all."
Track president Gillian Zucker had no explanation for why SAFER barriers were not in place where Hamlin's car hit the wall. She said that while the track pays for barriers, NASCAR makes the recommendation for where to put them.
She said the area where Hamlin hit was not among the recommendations.
"Anytime that NASCAR makes any recommendation that they feel will reduce injuries or the threat to injuries, we will always implement that," Zucker told ESPN.com. "We made a bunch of changes on the back stretch in the last couple of years.
"I'm sure that every incident that occurs, NASCAR reviews and determines whether anything needs to be done."
Zucker did not know why it wasn't recommended that the entire inside retaining wall be covered.
"This is a constantly revolving project," she said. "When barriers first came, we certainly didn't put them all around the facility. Then NASCAR made recommendations and we added more here and more here."
NASCAR officials said they will review what happened in Hamlin's wreck and make recommendations for improvements if warranted.
There is an approximately 2,000-foot gap going into Turn 1 and out of Turn 2, as well as a gap going into Turn 3 and out of Turn 4 where Hamlin hit that is not covered by SAFER barriers. There also is approximately 135 feet of grass that Hamlin's car slid through before reaching the wall.
NASCAR works in conjunction with the University of Nebraska's Midwest Roadside Safety Facility division that developed SAFER barriers and the IndyCar Series to develop safety technology.
The studies that pertain to SAFER barriers take into consideration the angles and the areas of the racetrack that have the highest frequency and likelihood of impacts.
Track officials said SAFER barrier recommendations are based on past history, and this incident happened where NASCAR never has seen an incident occur.
Dr. Dean Sicking of the University of Nebraska said the goal is to one day have every wall at every track covered by the energy-reduction system.
The problem, he said, is expense. It cost a two-mile track such as Auto Club Speedway approximately $6 million to cover the outside retaining wall at $500 a square foot.
So for an organization such as International Speedway Corporation that runs Sprint Cup events at 12 tracks just to cover the outside wall, there was an initial investment of more than $60 million.
There also weren't enough parts when the process began to cover all the tracks, so management had to implement them based on availability.
"We were only able to treat about a third of them," Sicking said of the initial wave of barriers. "Incrementally, we've been covering more and more of the track."
Many times, that is mandated by a wreck such as Hamlin's. For example, Richmond added more barriers after Jeff Gordon's hard crash into an uncovered concrete wall inside the back stretch in 2011.
"Whenever a wreck happens, NASAR looks at it and has us look at it," Sicking said. "We identify the speed and angle of the hit. If it seems to be significant, which clearly Denny Hamlin's would be, then we'll look at putting barriers at all tracks with a similar location to that one.
"We don't just treat the track that had the accident."
Sicking said SAFER barriers, based on a car hitting a wall at a 25-degree angle at 140 mph, will reduce the impact force by 70 to 75 percent. Although he hasn't seen video of Hamlin's hit, he said it would be almost impossible to predict the barrier would have prevented him from not being hurt.
"He still may have had some injury that's unknowable," Sicking said.
But Sicking does believe SAFER barriers save lives and prevent injuries from being more serious.
"SAFER barriers get hit hundreds of times a year and you never hear about it," he said. "But the three times somebody doesn't hit a barrier and gets hurt, you remember it."