LSU doesn’t have a backup defensive coordinator.

They don’t have any 5-star recruits awaiting their opportunity to ascend to the position.

That’s too bad.

If any starter on this team had performed at a level comparable to that of defensive coordinator Bo Pelini, he would have been replaced by now.

A backup would have become a starter.

It wouldn’t even have to have been a 5-star recruit. It would just have to have been someone else — anyone else.

The latest in a string of failures by Pelini’s defense came in Saturday’s 48-11 loss at Auburn.

LSU gave up more than 500 yards and more than 40 points – just as they did in their other two losses.

Sure, LSU and Auburn played to a scoreless tie through one quarter, but that just means LSU gave up 48 points in three quarters.

Sure, TJ Finley’s fumble was returned for a touchdown, and his 2 interceptions gave Auburn short fields that produced 2 other touchdowns. But Auburn called off the dogs when they pulled Bo Nix early in the fourth quarter.

There’s no sugar-coating or rationalizing that can change the fact that Pelini’s defense has been the biggest culprit in the Tigers’ 2-3 record.

They gave up 623 passing yards – that’s a 6, a 2 and a 3 – in the season opener against Mississippi State. That was an opponent playing its first game under a new head coach with a new system operated by a new quarterback.

That was an opponent that has not won since.

The defense played better a week later and took advantage of an outmanned opponent in a victory against Vanderbilt.

It still gave up 153 rushing yards. To Vanderbilt.

Then came another 500-plus-yard meltdown (and a season-worst 8.6 yards per play) against a Missouri team that scored 45 points in its win against LSU after scoring a total of 31 in losing its first two games.

Though the LSU defense gave up “just” 403 total yards in a 52-24 victory against South Carolina, it still allowed 7.9 yards per play. Pelini’s defense managed 5 sacks, but mostly it was hidden on the sideline while the offense possessed the ball most of the game.

Then came Auburn.

After the scoreless first quarter came a 21-point second quarter and a 21-point third quarter. Nix managed a 91-yard touchdown pass in the fourth quarter before taking the rest of the game off.

Pelini delayed the defense’s collapse for one quarter, but then it displayed the same shortcomings it has displayed with regularity this season.

It had mental breakdowns. It had physical breakdowns. It was confused by misdirection. It missed tackles. It socially distanced itself from ball carriers and pass catchers.

Pelini has said he has simplified the defense, but he has not improved the defense.

LSU is inexperienced but talented on defense.

Pelini’s defense shouldn’t be as bad as it is.

He is being paid $2.3 million per season. He is the second-highest-paid assistant coach in the country. His annual salary is $200,000 less than that of former LSU and current Auburn defensive coordinator Kevin Steele, whose defense overwhelmed the LSU offense Saturday.

Steele earned his salary Saturday.

It was four years ago when LSU left Jordan-Hare Stadium after another disappointing loss.

That 18-13 loss that dropped LSU to 2-2 was a bad performance, but it wasn’t as bad as this one.

But it was bad enough for then-athletic director Joe Alleva and the school administration to make a change – to fire the second-winningest head coach in school history (Les Miles) and replace him with a defensive line coach named Ed Orgeron.

When Orgeron accepted the interim position as head coach, he was decisive. The offense needed an immediate and dramatic makeover.

Orgeron fired coordinator Cam Cameron and promoted tight ends coach Steve Ensminger to replace him.

Does Orgeron look at the defensive staff and see someone he can turn to the way he turned to Ensminger four years ago?

Pelini’s specialty is supposed to be linebackers, so looking there is not going to work.

There is no visible evidence from the play of the secondary or defensive line that suggests that turning to cornerbacks coach Corey Raymond, safeties coach Bill Busch or defensive line coach Bill Johnson is likely to produce appreciable improvement.

But improvement has to come from somewhere.

LSU has an open date before facing No. 2 Alabama and Mac Jones and the prospect for an historical surrendering of yards and points.

Orgeron was asked after the loss to Auburn about potential changes on the defensive staff, or perhaps a shuffling of responsibilities.

He said he evaluates the staff every day. He said they’ll continue to work to get better.

He said they need to go through a full season before making any staff changes.

But as Orgeron ponders recruiting priorities for next season, he might want to add defensive coordinator to the list.