So Petrus began sparring with Antoine Sharp, Arkansas' strength and conditioning coordinator for football.
Forced to sit out last season because of academic issues, Petrus spent much of his time away from the practice field with boxing gloves on his hands, throwing jabs at pads held by Sharp.
"The boxing was all new, and it took awhile," Petrus said. "But I started getting it down and started figuring out how to move with it, and it's really helped me."
Without Petrus in the lineup last season, Arkansas' offensive line looked like a punching bag as it allowed 3.8 sacks per game, ahead of only Hawaii (4.07) for second-worst in the nation.
But Petrus has spent the first two weeks of spring practice working with the first-team offensive line, and assuming he can take care of his class work, he hopes to provide a boost upfront as a senior.
In a move intended to bolster the offensive line, Petrus was moved last week from the weakside offensive guard position to the strongside spot.
"He has gotten a little more athletic in what he does, not as robotic," Arkansas offensive line coach Mike Summers said of Petrus. "Certainly, he's always had great strength, but it's more functional strength now."
After moving from fullback to start 12 games on the offensive line in 2007, Petrus was expected to have a breakout season a year ago. He was voted by the Southeastern Conference's coaches to the preseason All-SEC second team, but he never got a chance to build on that.
Petrus was declared ineligible to play, forcing him to use his redshirt season to remain with the Razorbacks.
Arkansas coach Bobby Petrino hasn't said what led to the offensive guard being ruled ineligible, and Petrus didn't go into much detail when asked this week.
"By NCAA rules I was ineligible to play, but I'm proud that I didn't redshirt my freshman year," Petrus said. "I was fortunate I walked on and I got a scholarship, so I'm out here now.
"Fortunately, that's what saved me — having a redshirt year. And I'm out here now having fun with my teammates and that's the most important thing for me."
Petrus attended home games last season, but all he could do was stand on the sidelines and cheer on his teammates. He admitted he still has a hard time talking about everything that happened a year ago.
"He would come to some of the games and sit on the sideline with us, and I could tell he was fired up and wanted to be out there with us," Arkansas center Wade Grayson said. "... I think he's going to be ready to play this year."
Petrus spent much of his redshirt year taking part in a special workout designed by Arkansas' strength and conditioning staff. Along with boxing, the senior did some resistance work with bands to become more explosive off the line of scrimmage.
Getting stronger wasn't an issue, though. He recently bench-pressed 515 pounds, proving that he has power to go along with his quicker hands.
"Those (boxing) moves were helping me get my first step off the ball or get my hands up. That's what that has really helped me do," Petrus said.
"And when I do extend or do punch, it's a lot faster. You want speed and power, that's the name of the game."
Position: Offensive guard
Weight: 315 pounds
Notable: Petrus has returned to Arkansas' first-team offensive line after redshirting last season. He was ruled academically ineligible to play. ... A former fullback, he started 12 games as a junior in 2008 and helped clear the way for running backs Darren McFadden and Felix Jones. ... Petrus has been moved to the strongside offensive guard position, where he's blocking next to offensive tackle DeMarcus Love.