Gallman also isn't unique in trying to emulate Peterson. The difference: He comes closer than most, according to someone who knows firsthand. Clemson defensive coordinator Brent Venables saw Peterson blossom at Oklahoma while serving as the Sooners' defensive coordinator during Peterson's time there (2004-06).
In Gallman, Venables sees traces of A.D.
"Coach Venables is always telling me that me and Adrian Peterson have the same body type, being around that 215 range and trying to push to get to around 217, 220 this season," Gallman said. "Coach Venables has told me, 'You kind of run the same.'"
It's an endorsement of sorts, one Gallman welcomes as he continues his evolution at Clemson. Other than quarterback Deshaun Watson, few Tigers made bigger strides in 2015 than Gallman, who rushed for a team-record 1,527 yards. He nearly doubled his rushing total from the previous year (769) and recorded 13 touchdowns, up from just four.
Along with Watson, Gallman solidified a Clemson run game that was in doubt coming out of 2014. While Watson understandably received more accolades, Gallman raced onto the national radar with a 187-yard performance in the ACC title game against North Carolina, followed by a 150-yard surge against Oklahoma in the College Football Playoff semifinal at the Orange Bowl.
"I saw myself taking control and really tried to be a game-changer," Gallman said. "I thought I was a difference-maker."
After the season, Gallman reviewed all 283 carries he logged in games, as well as his practice reps. At first, he saw an enthusiastic back "just excited to play," but lacking precision on his run tracks. He would race to the C-gap (between the tackle and the tight end) when a play called for him to hit the A-gap (between the center and guard).
Gallman saw a shift during Clemson's game against Notre Dame, played in heavy rain after flooding. While he might have been better off playing in galoshes, he sloshed his way to a game-high 111 rush yards, more than double the total of any Irish player. He displayed a more physical edge on inside runs, while maintaining his speed.
Gallman eclipsed 100 rush yards in nine of 11 games leading into the CFP national title game before Alabama held him to a season-low 45 yards.
While Clemson endured an exodus of draft-eligible players, especially in the secondary, Gallman opted to return, tweeting his announcement with a picture of him crossing the goal line at the Orange Bowl.
— #9️⃣ (@Wanye_Kanye) January 13, 2016
"The big challenge for him coming back was, 'I want you to prepare like a pro,'" said Tony Elliott, Clemson's co-offensive coordinator and running backs coach. "You want to be an NFL guy, you need to be a master of your craft. You'll see a lot more big plays out of him, but it's going to be a result of him mastering the details."
Elliott preaches patience to Gallman, who at times will create plays alone rather than let his linemen work for him. Coaches peg Clemson's offensive line development as the biggest reason for the team's jump, and Gallman has greater awareness of his blockers and faith that they'll create openings.
Gallman also wants to evolve without the ball and has made pass protection a priority this spring.
"[Venables] said Adrian Peterson was the best practice player he's ever seen," Gallman said, "so I try to take advantage of every practice and get better."
Both Gallman and Watson eclipsed 200 carries last fall, while no other Tigers player had more than 42. Elliott expects to lighten Gallman's workload with a stronger No. 2 back, whether it's sophomore Adam Choice, returning from an ACL tear sustained in 2014, sophomore C.J. Fuller or junior Tyson Dye. The goal for Gallman is efficiency.
"I think you'll see a more polished guy," Elliott said.
"Ever since I’ve been playing, I’ve naturally gotten better the next year," Gallman said. "It's just a natural thing. I already feel like I've taken another step."