Editor’s note: This is part five in a weeklong series looking at Auburn’s top five position groups with room to improve.

AUBURN, Ala. -- Auburn literally ran its way to the BCS title game, rushing for 368 yards per game in the team’s last five wins to close out the regular season. However, what was lost in that magical run was that while the Tigers were running all over its opponents, its opponents were also running over them.

Auburn’s defense allowed over 200 yards rushing in four of those last five games. Even Arkansas and Tennessee, two non-bowl-eligible teams rushed for over 220 yards against the SEC champs.

So what’s the problem or more importantly, who’s to blame?

There’s not one single unit at fault. Part of the blame falls on the defensive line, which was effective rushing the passer but struggled against the run. Part of the blame probably falls on the secondary for allowing good runs to become great runs. But if you’re looking for a scapegoat, look no further than the linebackers.

It’s a group that had its moments in 2013 but ultimately needs to play better if this Auburn defense wants to improve in Year 2 under defensive coordinator Ellis Johnson.

Battling for No. 1: Before we go and start putting all the blame on the linebackers, let’s not forget that Cassanova McKinzy, the team’s weakside linebacker, had a very solid season. The sophomore led the team with 75 tackles, including eight tackles for loss. Barring injury, he’s entrenched as a starter heading into next season. At middle linebacker, last year’s combination of Jake Holland and Kris Frost played well at times, but the duo was inconsistent overall. Holland graduated which leaves an opportunity for Frost to take sole possession of the job, but he’ll have to earn it by fending off some of the up-and-comers. The other question mark is at the Star, a hybrid position between linebacker and defensive back. Robenson Therezie started every game last year, but his lack of size hurt Auburn at times against the run.

Strength in numbers: The most experienced backup is junior-to-be Anthony Swain. He played in all 14 games last season and finished 13th on the team with 26 tackles. He’ll likely backup McKinzy on the weakside, but he has the size to play middle, too. After Swain, there are still a number of players who could see action this year including JaViere Mitchell, who made two key fourth-down stops against Arkansas, and Kenny Flowers, a junior-college transfer who played in 11 games. The player to watch this spring is Justin Garrett. He was the team’s MVP last spring and was slotted to start at the Star before a multitude of foot injuries limited him to just two games. If Auburn can get him back healthy, it could provide a huge boost for this defense.

New on the scene: The most likely player to push Frost at middle linebacker is one that’s not even on campus yet. ESPN 300 linebacker Tre Williams signed with Auburn in hopes of early playing time, and though he probably has the talent to start from Day 1, he knows he still has to earn it. As a senior, Williams finished with 119 tackles and was named to the all-state team. Don’t be surprised if it turns into another time share between he and Frost, similar to what the Tigers used last year. Auburn also signed Derrick Moncrief, the nation’s No. 1 junior college outside linebacker. Moncrief enrolled early, which gives him the advantage of going through spring practice, and he’s expected to push for immediate playing time at the Star.