At LSU, “DBU” isn’t just a catchy slogan. It’s a mindset, an attitude, passed torch-like from one player to come through the LSU secondary to the next to the next.

“You have to show that swagger,” said senior safety Jalen Mills, soon to be one of the latest graduates of “Defensive Back University” to the NFL.

Junior cornerback Tre’Davious White is in an even more mentoring mode than most.

White was voted to receive the No. 18 jersey by his teammates, a symbol of leadership worn like a badge of pride on and off the field.

He has communicated with his young teammates what is expected of them going into this 2015 season.

“The cornerbacks have a group text going on,” White said. “I texted them before camp and I told them the standard for defensive backs here is very high.

“You have to be up to the task.”

Despite the team struggling to an 8-5 record last season, there is little argument LSU’s secondary was more than up to the task.

The Tigers led the Southeastern Conference in passing yards allowed and passing efficiency defense, finishing third nationally in both of those categories.

This season, there are questions about the quarterbacks, worries about depth on the defensive line and at linebacker.

But again, the secondary is expected to be a rock. And White said the defensive backs as a group have to be ready.

“We’re going to get everybody’s best shot every Saturday,” he said.

Still, this is college football, a sport of constant change from one season to the next.

While White (33 tackles in 2015, two interceptions, six pass deflections) fills the role of the proverbial cover corner, the other corner spot was left vacant when Jalen Collins bolted a year early for the NFL and was drafted in the second round by the Atlanta Falcons.

Sophomore Ed Paris (three tackles in 13 games played) is vying with freshmen Kevin Toliver II and Donte Jackson from Riverdale High School to be the starter.

Toliver, rated by some recruiting services as the nation’s No. 1 cornerback prospect, arrived in January and took part in spring practice. Jackson was ranked as the nation’s No. 1 overall athlete prospect.

“They’re smart, watching film and putting in the work,” White said of his young counterparts.

Dwayne Thomas, who was reinstated to the team just before the start of preseason camp, is White’s backup. Thomas had been suspended in June with quarterback Anthony Jennings for unlawful entry into an apartment.

Based on experience, Paris should be considered the favorite to get the start in No. 13-ranked LSU’s Sept. 5 season opener against McNeese State, but Saturday night’s scrimmage in Tiger Stadium may go a long way to deciding who stays with the first team.

The starting safety spots are no contests. Like White, sophomore Jamal Adams (66 tackles, five PBUs) is a serious All-American candidate. He’ll be backed up by junior Corey Thompson, who missed the 2014 season with an ACL tear, and start opposite Mills (62 tackles, one interception, five PBUs). Behind Mills is junior Rickey Jefferson, younger brother of former LSU quarterback Jordan Jefferson.

Despite his experience, Mills isn’t taking his starting spot for granted.

“The coaches are always recruiting someone to replace you,” he said. “To push you further than you think you can go.”

The classes at DBU are always in session.

POSITION PREVIEW SERIES

Monday: Defensive line

Tuesday: Linebackers

Wednesday: Offensive line

Thursday: Backfield

Friday: Quarterbacks

Saturday: Secondary

Follow Scott Rabalais on Twitter, @RabalaisAdv.