There usually are pros and cons to any new job.

Take Dion "Rocko" Williams. He doesn't get to hit anybody in his current job, which he considers a negative. But he doesn't get hit anymore, either, which he and the physicians who once told him he could no longer risk that in his old job definitely consider a plus.

Williams is the front-tire changer for the No. 45 Dodge driven by Kyle Petty for Petty Enterprises in the Nextel Cup Series. He also serves as a part-time pit coach for other teams, including the Circle Bar Racing team in the Craftsman Truck Series.

He basically traded one uniform in for another about three years ago, when the sixth concussion of his long football career cut short his dreams of playing in the NFL and steered him toward NASCAR. A hard-hitting linebacker in college at Wake Forest, where he played from 1999 through 2004, Williams was in camp as a free agent with the Minnesota Vikings when he suffered the decisive blow that caused an immediate and unforeseen career change.

"I had six concussions; I had five prior in college and I had my sixth one in the third preseason game with the Vikings," said Williams, an African-American. "After that, I became a liability. It was sort of suggested, 'Hey, don't put a helmet on anymore as far as full-contact sport because it could cause serious brain damage.' So I was kind of upset about that. If it wasn't for NASCAR, I think I would have had a more difficult time with it. That made the transition of leaving football a little bit easier."

It wasn't planned. Not even close.

"I lived 20 minutes from Atlanta Motor Speedway growing up and never knew it existed. I had been in football my whole life," Williams said.

Then he met a Wake Forest football fan who also happened to race in NASCAR's Modified Series at Bowman Gray Stadium in Winston-Salem, N.C. The fan/driver helped get Williams' car painted when Williams was still in college, and one day invited him to check out his racecar.

"I said, 'That's pretty cool. I've never seen a real racecar in my whole life,'" Williams said. "Next thing you know, he asked me, 'Hey, man, you want to be part of my pit crew?' I said, 'What's that?' Basically it was more like security detail, because he liked to run off at the mouth and get into fights at Bowman Gray -- and when he had me there with him, nobody really messed with him, a little short guy.

"But I learned so much in that year and I really got interested in it. He told me, 'You hang around me, man, and people are going to notice, and with your athletic ability I think you've got a future in pit crew.'"

The man was right. Williams said that it didn't take him long to understand that there are many subtle similarities between football and racing, especially when it comes to preparation for game, er race day.

"It's really not too much difference from with football. It's a lot of training, a lot of physical training, working out three to four times a week. You've got to be flexible," he said. "There's even film study. The movements through the pit stops are based on fundamentally sound movements. To be fundamentally sound, you have to study yourself a lot.

"Strength is definitely an advantage for me, and my speed and quickness and my footwork. You're jumping over tires, feet, hoses. All of that has helped me move up in the sport a lot faster."

The 6-foot-1 Williams said that he is 15 pounds lighter now than his college playing weight of 255 pounds, but that, strangely, he is stronger. That is saying something, since he benched 455 pounds while at Wake.

After the brief stint at Bowman Gray, Williams was trying to figure out what to do with the rest of his life when he learned through the career-development folks at Wake Forest that Chip Ganassi Racing was looking to audition some athletes for possible pit-crew positions.

"Me and six other guys went down to Chip Ganassi, they introduced us to the program, we trained for about six weeks, and the rest is history," he said.

He made the switch from Ganassi to Petty Enterprises because he likes being a part of the Petty program, which is so rich in history, and because it affords him the freedom to work on the side as an "independent contractor," selling his services as a pit coach to some other truck teams on the side.

"I'm coaching now and have a lot more freedom -- not to mention that it's a smaller team. The Pettys are a great organization," Williams said. "They're good people to work for, and I enjoy working for them."

He still recalls the first time he met the King, NASCAR legend Richard Petty.

"The first time I met him, I was kind of shocked because I had heard so much about him -- and he came right up to me and took his hat off and put it on my head. And he was like, 'What's up, man?' I was like, 'This is the King?'" Williams said.

"It didn't really hit me initially. But afterward people kept coming up to me and saying, 'You know that was the King right there?' They were so excited about what he did and how he reacted to me, I really appreciated it a lot more. I was like, 'Wow. This is a living legend right here.'"

Now Williams says he would like to be a part of helping Petty Enterprises stage a resurgence in Cup racing success. The team hasn't won a race since John Andretti wheeled the No. 43 Dodge to Victory Lane in 1999.

"Even though we don't run up front all the time -- and I had a lot of other offers from other big-time Cup teams -- it's not always about the money and it's not all about the fame and the glory. It's more about liking what you're doing and liking who you work for. And being part of something. It's like when I was playing at Wake Forest and no one even knew they had a football program. We came in and went to three bowl games," Williams said.

"I look at Petty as a team on the rise. So why would I join a team that's already up there? I think Petty is going in the right direction and now I can say I'm part of the reason why they made it back to Victory Lane."

He's going to attempt to do it one second, and one tire, at a time. That's how quickly he is supposed to hoist a tire into proper position during pit stops.

"I do miss hitting people. It was my stress reliever," Williams said. "When I was mad during the week, I could get it out in a practice or a game. Now I can't really hit anybody, so I have to channel that energy into my performance on these tires. ... In a high-pressure situation, I challenge myself to be perfect. That's how I handle it."