Like a drum major leading a marching band, Leonard Williams leans back and then high-steps from the end zone to the 30-yard line, pumping his arms high above his shoulder pads.
The 6-foot-5, 300-pound USC defensive lineman has just completed one practice drill and is rollicking as he hustles to another.
Williams greets a teammate, throws back his head, rolls his shoulders and swivels his hips as music blares from sideline speakers.
Williams' unbridled joy is on display each time USC practices for Saturday's Holiday Bowl. He appears to be having the time of his life, soaking in each moment of every workout, as if they might be his last with the Trojans.
Williams earnestly says he has not decided whether he will forgo his final season of eligibility and make himself available for the 2015 NFL draft. But he is expected to go. The two-time All-American is regarded as a possible top-five pick.
Turning pro and earning millions of dollars seems like a foregone conclusion to everyone except Williams, who sounds as if he still must convince himself.
"Once you go to the NFL it's like, you're done," he said. "You're part of the real world.
"You're grown up."
Williams was considered the No. 1 overall pick in the draft according to some projections at the start of this season. He has the size, strength and tenacity of a player who could have an immediate impact in the NFL.
Williams, 20, underwent shoulder surgery after last season. Coaches and trainers have helped him through ankle and shoulder issues through part of this season.
But his stock has not dipped much, if at all.
"Before I went in there, I thought this guy had a lot of hype," an NFL scout told The Times' Sam Farmer in November. "When I saw him, I thought he was the real deal."
Williams' six sacks pale in comparison to other nationally decorated linemen, but statistics can be misleading. Williams is listed as a defensive end but does not typically play on the edge in the Trojans' 3-4 hybrid scheme. Instead, he handles double teams in the interior, shedding blocks and directing ballcarriers to linebackers.
Shoulder issues caused coaches and trainers to hold Williams out of some practices, but he played with unrivaled intensity in games.
"He's not anywhere close to being tapped out in terms of his potential," said Justin Wilcox, USC's defensive coordinator.
Williams will have left an imprint if he leaves USC after Saturday's game against Nebraska.
Quarterback Cody Kessler set several school passing records this season and could break more. Tailback Javorius Allen also starred at times. But teammates voted Williams the most valuable player.
"I actually thought Cody Kessler was going to win — he had an outstanding performance this year," Williams said, adding, "It was an honor to be mentioned as the MVP."
Coach Steve Sarkisian was not surprised by the vote, or by Williams' humble comments.
"It's not about him," Sarkisian said. "It's about everybody else."
Monte Kiffin walked out of his office with his head down after receiving a phone call. It was Jan. 31, 2012, the day before high school players could sign letters of intent, and USC's former defensive coordinator was about to deliver some bad news.
"Leonard's going to Florida," he told the staff.
It wasn't a huge surprise. Williams, one of five children, attended Mainland High in Daytona Beach, Fla. He wore Florida Gators apparel to school — shirts, pants, even shoes.
"We were just like big Gator fans," he said.
But Ed Orgeron would not take no for an answer. The Trojans' former defensive line coach and recruiting coordinator, fueled by caffeine and beef jerky, went into overdrive.
"That's when the Red Bull and the Slim Jims kick in," Orgeron said, laughing.
USC coaches worked the phones throughout the night, convincing Williams that USC provided the best opportunity to reach his NFL dreams.
"At midnight California time, Leonard was a Gator," Orgeron said. "At 6'o'clock, Leonard was a Trojan."
Williams said that after he called Kiffin, he huddled with his high school coach and weighed the pros and cons of attending Florida or USC. The opportunity to establish his independence away from home played a major role on his decision.
"It was just a feeling," he said. "Wherever my heart takes me that's where I go.
"That's how I'm going to feel about the decision about going to the NFL as well."
It was the first day of summer workouts in 2012 and senior defensive end Wes Horton welcomed Williams with a flurry of information.
At Orgeron's request, Horton sized up the incoming freshman and launched into a critique of what Williams could do better. He demonstrated moves Williams had not seen before.
"He was looking at me with wide-open eyes," Horton said, "just soaking in everything."
The mentoring by Horton, now into his second season with the Carolina Panthers, extended into the meeting and locker rooms.
"I listened to everything he said," Williams said, "because he had been through it."
Williams was a starter by the third game of the season and a freshman All-American at the end of it.
As a sophomore, after he recorded 13 1/2 tackles for losses, he was selected to ESPN.com's All-America team.
"I have been around USC for over 40 years," Athletic Director Pat Haden famously tweeted in November 2013. "Leonard is one of the top 5 players I have seen. He is that good."
Despite his size and high profile, Williams remains a child at heart. He still rides a skateboard across campus, his curly mane blowing in the wind.
"The only difference is he's gotten a little bit older and little bit more facial hair," said sophomore linebacker Quinton Powell, who followed Williams from Mainland High. "That's about it."
Horton won't be surprised if Williams takes the NFL by storm.
"When you've got a heart like Leonard," Horton said, "you're going to be all over the field."
Williams experienced his share of adversity at USC.
Kiffin, a point man in his recruitment, was fired after the 2012 season.
"I was like, 'Man, this is cold-blooded business," Williams said. "I came here for a specific coach and now he's not even here anymore."
Former head coach Lane Kiffin, Monte's son, was fired five games into the 2013 season. And Orgeron, Williams' position coach, rejuvenated the Trojans as the interim leader but abruptly exited when USC hired Sarkisian.
"I was like, 'Man, did he really care about me like he said he did?'" Williams said, adding, "A bunch of bad thoughts were going through my head."
Many players gathered off campus after Orgeron addressed the team at the McKay Center. "That was like the toughest," Williams said. "Everybody was crying."
Williams and Orgeron remain in contact. "I still keep in touch with Coach O," Williams said. "He's a great guy. I look forward to having him as a great resource for the rest of my life."
Orgeron said he would always remember how "Big Lenny" handled the pressure of playing as a freshman. How he never blinked when the gravel-voiced coach shouted instructions. How he rose to the occasion in a game's biggest moments.
"I'm sure," Orgeron said, chuckling, "he can hear that voice every once in awhile."
Williams truly sounds torn between staying at USC or going to the NFL. But there are practical as well as emotional factors that will weigh in his ultimate decision.
Williams is a top pro prospect. He has suffered no major injuries.
He also is a father. His 2-year-old daughter, Leana, lives in Florida with her mother.
"I definitely tie a lot of stuff into it and having a daughter is a big part," he said. "I know I need to take care of her."
A financial windfall as a top NFL draft pick would not make leaving USC any easier.
Williams punctuates a conversation with multiple references to the USC teammates, coaches and administrators who helped him mature.
Most players come to USC hoping for NFL opportunities. Williams' is beckoning.
"I definitely wanted it to come to this point," he said. "Now that I'm at this point, I feel like I'm not finishing what I started.
"I feel like I'm getting cut short."
Follow Gary Klein on Twitter @latimesklein