FORT WORTH – Michael McDowell took his practice laps gingerly Saturday in a backup car, counting his blessings after walking away from its wrecked predecessor.

A day after barrel-rolling down Texas Motor Speedway, a sore McDowell was preparing for today's Samsung 500, in which he'll start 40th.

"It feels like the first day you go back to the gym," McDowell said. "Pretty amazing."

With McDowell's mishap replayed countless times around the country on television, the 23-year-old rookie from Phoenix displayed a self-deprecating sense of humor along with gratitude for safety advances.

"I feel grateful and blessed that I'm sitting here right now," McDowell said. "Five years ago, four years ago or maybe a year ago, I don't think that would have been possible."

Ty Norris, general manager for Michael Waltrip Racing, wondered if fluid left by a David Gilliland qualifying run and a chemical mixture used in cleanup might have been a factor. So did McDowell.

"When he went to the wall to make the wide entrance to the corner, I saw a lot of stuff kicking up," Norris said.

Robin Pemberton, NASCAR's vice president of competition, said the "stay dry" compounds used for oil cleanup played no role in McDowell's accident.

He did not want to speculate about causes until the car is examined early this week at NASCAR's research and development center.

Pemberton and Norris each noted innovations that contributed to McDowell escaping injury – from SAFER barriers and the head-and-neck restraints to the remodeled Cup car.

Norris called it the most violent accident he had seen in 20 years.

"For him to pop out of there and walk away like he just stepped in a pothole and twisted his ankle was pretty amazing," Norris said.

A 28-foot section of the Turn 1 wall weighing six tons was replaced Friday night. A crew of 10 workers needed nearly three hours to finish repairs, TMS president Eddie Gossage said.

What is left of McDowell's Toyota Camry will probably become a showroom piece at Michael Waltrip Racing in North Carolina, complete with McDowell's good-luck pine tree air freshener.

As for McDowell, he joked that he's finished being the crash-test dummy for the Car of Tomorrow.

ccarlton@dallasnews.com

rdurrett@dallasnews.com