LSU changed its defense to a 4-3 base for the upcoming season because it had so much depth along the line.

Some of that depth has vanished with the season-opener against Mississippi State looming Sept. 26 in Tiger Stadium.

The Tigers were down to 8 defensive linemen after losing 5 of them, but they finally got some good news Monday. That’s when senior Neil Farrell Jr., a projected starter at either tackle or end, confirmed that he would be returning.

He had opted out of the season last month because of family considerations related to COVID-19.

Farrell, who had planned to return in 2021 for his final season of eligibility, hinted last week that a return was a possibility when he tweeted, “My grandmother is getting better each and every day & I thank God for that … I miss football.”

His return was especially helpful in the wake of Tyler Shlevin’s decision to opt out and prepare for the NFL Draft. Shelvin was expected to be one of the top playmakers on the defense this season.

Justin Thomas and former tight end TK McLendon also left the team, and end Ray Parker was suspended from the team last week.

Thomas, who was competing for a starting spot at end, left the team before preseason practice began. Reportedly he has enrolled at UAB, where he will sit out this season.

“It’s unfortunate,” coach Ed Orgeron said of Thomas’ departure.

Thomas played in 5 games as a backup last season before withdrawing from school for personal reasons in mid-October. He returned in February and appeared to have positioned himself for significant playing time before leaving the team again.

Orgeron announced last week that Parker, who redshirted as a freshman last season, was suspended indefinitely for an unspecified violation of team rules.

So Orgeron, first-year coordinator Bo Pelini and defensive line coach Bill Johnson have to go deeper into a depth chart that features a lot of inexperienced players in order to fill out a rotation for the season opener against Mississippi State on Sept. 26 in Tiger Stadium.

“At defensive line, we have a lot of depth,” Orgeron said before Shelvin’s departure. “We can rotate those guys.”

There has been a lot of rotating happening already. Glen Logan, who can play tackle or end, and Apu Ika will now be counted on more on the inside in the absence of Shelvin.

Much of the interior depth is inexperienced but promising with 3 freshmen who are 4-star recruits – Eric Taylor, Jaquelin Roy (who can play outside also) and Jacobian Guillory.

The most noticeable difference between Pelini’s 4-3 scheme and former coordinator Dave Aranda’s 3-4 scheme should be the presence of an edge rusher operating out of a three-point stance rather than a two-point stance.

But things aren’t all that different. In fact, when the Tigers began preseason practice the two starting defensive ends were former outside linebackers Andre Anthony and Travez Moore.

Aside from Logan’s ability to slide outside, the depth at end also is inexperienced. Four-star recruit BJ Ojulari is a freshman as is Phillip Webb, and JUCO transfer Ali Gaye is an intriguing prospect at 6-7.

“We have Andre Anthony doing very well,” Orgeron said. “The young guys behind him like Phillip Webb and BJ Ojulari I think they are outstanding pass rushers. Travez Moore is doing great at left end and he’s actually starting at left end. Those guys are doing phenomenal. I feel good about Andre Anthony and I feel good about the direction we are going with the 4-3.”

The Tigers lost 2 of their top lineman from last season – Rashard Lawrence and Breiden Fehoko – to the NFL. And now 2 more veterans are gone.

So they will be counting on a few familiar faces to handle bigger roles than they had last season as well as a lot of newcomers to contribute significantly right away.

Orgeron believes there’s still more than enough talent on hand to help Pelini make the new scheme work, even if some of the talent is missing.