TALLADEGA, Ala. -- Denny Hamlin was released Monday morning after spending the night in a Birmingham hospital for evaluation after a tire failure led to a hard crash at Talladega Superspeedway.
Hamlin was alert and awake when he was transported to the UAB Medical Center on Sunday, but was complaining of a headache and possibly had a concussion. He was also favoring his right foot after a slow exit from his crumpled car.
"The tire went down and it was quite a shot," Joe Gibbs Racing president J.D. Gibbs said. "He's got a little headache, so they're just going to watch him. It was a scary deal, but it's at least nice that he's alert and with it."
Hamlin, one of 12 drivers racing for the Sprint Cup title, was leading midway through the race when his right front tire failed and his Toyota shot into the outside wall. He said nothing over his in-car radio after the hit and took several moments to get out of the car.
Crew chief Mike Ford said he was unsure what happened to the tire, and did not have a chance to speak to Hamlin.
"But it happened so fast, I doubt he even knows," Ford said.
Hamlin was 39th in the race and fell to 12th in the Chase standings. Teammate Tony Stewart won the race.
Hamlin's tire failure was the fourth one in the race and fifth of the weekend. Earlier, Brian Vickers' tire exploded as he was racing for the lead and it triggered an eight-car accident.
"I felt a bomb explode in my right front tire," Vickers said. "I just went down into the tri-oval and it didn't cut or go flat -- it exploded. I saw the right front fender going through the air before the front of the car even dropped. It was the same thing that happened to [Dale Earnhardt Jr.] in practice."
Earnhardt had a tire failure during a Friday practice session that triggered a multicar accident.
Ford said on the run before Hamlin's tire failure, the right rear tire had several cuts in it when the crew removed it during a pit stop. Hamlin attributed the cuts to debris on the race track, so Ford said it was unclear if the later failure was caused by Hamlin running over something or a deficiency in the Goodyear product.
Rick Heinrich, product manager for Goodyear, said the tires used Sunday are the same that were used without incident in the spring event at Talladega. He said David Reutimann's earlier tire failure had "100 percent evidence of a puncture" and Goodyear will have to analyze the other issues at its Akron, Ohio, plant.
"There's a tremendous amount of car contact out there and that loosens things up and drops things on the track," Heinrich said. "There's been accidents. Can't say for sure in every case what happened, but we'll continue to look at it."
Goodyear, meanwhile, is returning to Indianapolis Motor Speedway next week for a two-day tire test to determine why its rubber failed to hold up during the July race. Cars could run about 10 laps without risk of tire failure, and NASCAR called mandatory cautions that forced teams to change the tires and not push them beyond the limit.
Information from The Associated Press was used in this report.