Fixing the defense is Auburn's top priority

There's no secret as to why Auburn lost three of its final four regular-season games. Sure, turnovers (or lack thereof) might have played a role. Injuries to key playmakers certainly didn't help. But let's not kid ourselves. It was the defense.

It's why Ellis Johnson was let go after the season. It's why ex-Florida coach Will Muschamp was brought back to the Plains as the new defensive coordinator. And it's why even more staff changes were made on the defense this week.

The Tigers (8-5) were just plain bad on that side of the ball, and it was no different in their bowl game. They gave up 400 rushing yards to Wisconsin. That's right, 400 rushing yards, to a team who basically said we're not going to pass the ball in the second half. Auburn's defense knew what was coming, and they still couldn't stop it.

Heisman finalist Melvin Gordon finished with 251 rushing yards alone. That's the most ever allowed by Auburn, and the Tigers have been playing football there for over 100 years. Gordon also scored three touchdowns in the second half to keep the Badgers in it.

When the Tigers finally got a "stop," holding Wisconsin to a field goal in overtime, it was the offense that let them down.

But the problem isn't on offense. It's on the defense.

Still, there's hope. As mentioned above, Muschamp is taking over and he's got as good a track record as any defensive coordinator in college football. He even guided Auburn to back-to-back top-10 defenses when he was coordinator back in 2006 and 2007.

The cupboard isn't bare either. With Tuesday's news that linebacker Cassanova McKinzy will be returning to Auburn for his senior season, the Tigers might return as many as eight starters on the defense. They also add two potential starters in defensive end Carl Lawson, who is coming back from injury, and safety Tray Matthews, who sat out last season after transferring.

It's a unit that's going to have to play better, though, and it starts in two areas:

Generating a pass rush

This is what the Auburn defense has been predicated on the past two seasons. It's why Dee Ford was such an integral part of the 2013 team that made it all the way to the BCS National Championship. And it's why when Ford graduated and Lawson got hurt this spring, the defense never recovered.

The Tigers simply could not get to the quarterback. They finished 11th in the SEC with 21 sacks on the season and had just 10 sacks in conference play.

And when you're not getting pressure, it affects the whole defense. It leaves the secondary out to dry because they can't cover wide receivers for that long, and it forces you to blitz more with linebackers, leaving tight ends and running backs open.

The good news is that Muschamp's new defensive scheme should be more aggressive. He blitzes more and does a good job of disguising his blitzes with different looks. It also doesn't hurt that Lawson will be back to 100 percent. He holds the key.

Tackling better

Sounds easy, right? Well, this was a problem all season for Auburn, and it showed up more than ever in losses to Texas A&M, Georgia and Alabama down the stretch.

Midway through the season, Auburn even added a five-minute tackling circuit to its practice routine, but it didn't help. The Tigers continued to miss tackles, continued to give up extra yards and continued to give up the big play.

"We harp on explosive plays," Johnson said after the Texas A&M game. "Keeping runs under 15. Keeping passes under 20. It's hard for people to score without one of those. But we just keep finding a way to put them on the field."

Now it's Muschamp's turn to try and fix the problem. He preaches stick-and-wrap tackling, and that will likely be his first order of business when spring practice begins.

Allowing 251 yards to one player, even if it is a Heisman finalist, is unacceptable. This Auburn defense has too much talent on the roster to not be better at tackling. It's not a hard concept, but it will be critical if the Tigers want to turn things around in 2015.