Coordinators and coaches are important to a college football player’s success — just ask former Penn State QB Christian Hackenberg.

Under Bill O’Brien (now the head coach of the Houston Texans), Hackenberg was projected to possibly be the No. 1 overall pick in the NFL Draft.

When former Vanderbilt coach James Franklin took over for O’Brien, Hackenberg’s stats plummeted. He was taken by the New York Jets in the second round of this year’s NFL Draft — a pick that has been widely criticized.

Over at cbssports.com, Robby Kalland picked out four Heisman contenders who will be working with new coordinators this season, including two from the SEC.

The first, Georgia RB Nick Chubb, has a new head coach in Kirby Smart and a new offensive coordinator in Jim Chaney. Though Chubb will be forced to play in a new system, Kalland said that’s not the biggest challenge awaiting the talented back:

The issue for Chubb in being a Heisman contender this season won’t a scheme fit but rather usage. Chubb could see some of his workload go to Sony Michel, who had a big year in Chubb’s absence, rushing for over 1,100 yards and is a good pass catching option out of the backfield — 26 catches for 270 yards in 2015. Chaney has shown in the past that when he has two quality backs, he will split touches pretty evenly. Examples include Jonathan Williams at Alex Collins at Arkansas (nearly identical touches and numbers) and Raijon Neal and Marlon Lane Jr. at Tennessee. Simply put, Chubb may not get a workhorse share.

The other SEC player on Kalland’s list is Texas A&M WR Christian Kirk. Kirk has 80-to-1 odds to win the Heisman, according to the Westgate Las Vegas SuperBook.

Kirk’s new offensive coordinator is former UCLA OC Noel Mazzone, who runs a slower offense than the Aggies ran last year. Still, though, a new coordinator isn’t the biggest challenge facing Kirk.

Trevor Knight, a quarterback transfer from Oklahoma, will take over for Kyle Allen and Kyler Murray. Unless Knight and Kirk develop some instant chemistry, though, it’s unlikely Kirk’s Heisman hopes will go anywhere but down as the season wears on.