Out with the old and in with the new.

Following Thursday’s Outback Bowl against Wisconsin, recently departed coordinator Ellis Johnson and his 4-2-5 base defense will be no more at Auburn, a scheme that has opened the floodgates for big plays this season and squandered Auburn’s bid for a second straight SEC title.

Despite a sour end to a once promising season with three losses over the last four games, there’s reason to be excited during bowl week for the Tigers who believe they have an ace in the hole named Will Muschamp.

Perhaps you’ve heard of him?

Intrinsic to Auburn’s expected turnaround on defense in 2015, the former Florida coach and defensive play-caller on the Plains during the 2006-07 seasons is regarded as one of college football’s most sought-after defensive minds and became quite the free agent after Gators athletic director Jeremy Foley relieved him of his duties in November.

RELATED: Muschamp high on defensive personnel

Muschamp’s pressure-heavy 4-3 alignment could flourish with the proper personnel, pieces of the puzzle built through recruiting.

Muschamp will spend much of the Outback Bowl tinkering with imaginary two-deeps on his notepad, hoping to get a general idea of how his defense will look next season. During his first two weeks on the job, Muschamp has kept a healthy distance at practice and has allowed interim coordinator Charlie Harbison to coach the defense.

He won’t interfere until the new year.

“He’s just trying to get to know our players, evaluate our current guys and our players have responded extremely well,” Gus Malzahn said.

The obvious beneficiary of Muschamp’s hire will be defensive end Carl Lawson and his much-anticipated return. The Tigers weren’t fierce enough up front this season without their tenacious pass rusher who was sidelined with a knee injury.

RELATED: Harbison simplifying scheme for Outback Bowl

The bulk of Auburn’s returners on defense only know Muschamp from what they’ve seen through highlights — lots of yelling and screaming. A few, including Lawson, were recruited by their new DC.

“I recruited a bunch of them, so I am looking forward to coaching some of them who turned me down,” Muschamp said during his introductory presser. “When you lose a guy like Carl Lawson, a pass rusher like that, that is going to affect your coaching ability, I can tell you that right now. I’m looking forward to working with those guys, but we’ve got a good enough combination of guys. We’ll be fine.”

Finding the right fits for Muschamp won’t happen until spring practice, but best case scenario for Auburn is that junior linebackers Kris Frost and Cassanova McKinzy return. Both veteran anchors in the middle of his defense are considering an early exit to the NFL Draft.

Could a meeting with Malzahn and Muschamp prior to the Jan. 15 deadline sway their decisions?

“We’ve both been talking to each other through this whole entire process,” Frost said. “It kind of feels like recruiting all over again. We’ve both been weighing out the options of coming our early or staying. It’s all about how we feel, going into this bowl game how we play, what’s right for us, what’s the right business decision for us and our families. “