"We haven't had that in the past," said Luper. "The possibility of having four tailbacks is pretty exciting. It's good for competition. Some guys, we know what they can do and others, we want to see what they can do."
There's no mystery surrounding McCalebb, Auburn's most experienced tailback.
"If there's a hole, he's definitely going to get through it," said Luper. "The problem comes if there's not one. I don't know that he can make one, but don't let him surprise you. He can get it done."
Onterio McCalebb runs for big yardage vs. Virginia in Auburn's on New Year's Eve at the Georgia Dome to close the season.
Luper got a glimpse of what Mason can do when the sophomore played a larger role in the Chick-fil-A Bowl with Michael Dyer suspended. Mason said playing a larger role in the bowl game was a confidence booster for him going into the spring.
"I need to step it up and fill in for him, and I'm going to try and fill in the best," said Mason of taking over for Dyer. "I feel like I'm bigger, faster, stronger, which will help me towards this game. I'm understanding what college football is more about and becoming a better student of the game."
Tre Mason is shown in action last fall as a true freshman.
Luper said he thinks the confidence Mason gained against Virginia has carried over into spring practice.
"He's quick as a cat, he's smart, he's tough," Luper said. "I like what he's done physically to his body over the last few months.
"We're going to get the ball into his hands several different ways," noted Luper. "He can catch the football. We're going to be involved in the passing game a lot more from a tailback perspective, so excited to see Tre."
Luper said one emphasis for the running backs this spring is to have a "physical nature" when running the football. The addition of Illinois transfer fullback Jay Prosch will certainly help in that regard.
"They're not many guys that can power clean 400 pounds and can run like he can run and block like he can, are flexible like he can, has hands that he has," Luper said. "He's a prototype fullback. He's what you're looking for, and we're happy to have him
"He cleared some space for us today," added Luper. "He hits somebody everyday. There will not be a day that you could say ‘Jay Prosch, he didn't work today.'
Luper said Prosch is physical at the point of attack and has the potential to be a dominant fullback in the Southeastern Conference. He explained that Prosch will be used in multiple ways, including lining up in the backfield and out wide.
"Jay is going to be an integral part for us," he said. "They call him the ‘Juggernaut,' so we need the ‘Juggernaut.'"
Luper said Blakely and Grant are ready to go this spring and have the physicality to run between the tackles.
"It's just more of a mindset than anything," said the running backs coach. "It's what we're going to do. It's going to get done—that's the mindset we're taking into it."
"The expectations are high and never changed," added Luper. "They're working their way towards meeting those expectations, but they're ready to go."
Luper said another emphasis from day one of spring practice has been teaching the running backs how to protect the passer.
"In the evolution of the running back, that's one of the last things they learn, that they master, and probably that they want to do, but it's something that we focus on from day one, pass protection, in particular," Luper said. "Protecting the quarterback in this league, a physical league, you've got to protect the quarterback, you've got to be able to run the football, so it's something we start day one to emphasize and you get what you emphasize."
Even with the increased numbers, Mason said the running backs are focused on working together as one and getting the job done at tailback.
"Our competition is really high," Mason said. "We're all great friends. We're like brothers, all four of us. But we're all, you know, we got to eat and gain the starting position, and I'm just going to work my hardest for it."
The competition will continue for the tailbacks Wednesday morning when the Tigers hit the field for the fourth of 15 spring practices.