Replacing a horse like Marlon Mack is never easy, but it’s a necessity if the USF football team wants its record-setting offense to keep on rolling on.

Mack, the all-time leading rusher in Bulls history, declared for the NFL draft after his junior year, leaving a huge hole to fill.

But seniors D’Ernest Johnson and Darius Tice feel the USF run game will be in good hands.

 “We shouldn’t miss a beat,” Tice said.  “We should be fine.  We’re going to be fine.  Because what we’re running, all you’ve got to do is read what you’ve got to read and do your responsibility.”

Running backs will play a key role in new offensive coordinator Sterlin Gilbert's offense.

They'll be asked to relay signals from the bench to the offensive line in Gilbert's high-paced, no-huddle attack.

Tice is back for a fifth year after being granted a medical redshirt for 2017 following a season-ending injury against Florida State early last fall.

He’ll likely serve as a complimentary back to senior D’Ernest Johnson.

The versatile Johnson, who can also return kicks, had four games with over 90 yards from scrimmage in 2016.

He's now expected to be the primary ball carrier to fill Mack’s big shoes.

“It means a lot to me, and my family also, and the team,” Johnson said.  “I’m just going out there and just trying to do my best.  Just going out there and trying to have fun.”

Running backs coach Shaun King, a Gibbs High School graduate who used a huge senior year at Tulane to propel himself into being a second round NFL draft pick by the Buccaneers, believes Johnson could also explode in his final year of college eligibility.

“He doesn’t have a ceiling,” King said.  “Can I quote Jordan that, ‘the ceiling is the roof’ (laughs)?  No, he doesn't have a ceiling.  And I told him, you're one of those rare backs who can take it 80 (yards), who can get a yard in a tough situation."

The Bulls only currently have four backs on scholarship, but sophomore Trevon Sands and redshirt freshman Elijah Mack have proven this spring that they could provide quality depth.

“We’re all hard working,” Johnson said.  “We all come out here to compete each and every day.  We stay on each other.  I like our vibe- just going out there and pushing each other.”

And potentially pulling the Bulls to another double-digit win season.