Teryl Austin was a young defensive backs coach with the Seattle Seahawks in 2005 when they faced the Pittsburgh Steelers in the Super Bowl.

This was before the vaunted “Legion of Boom” years in Seattle, and Austin recalled the team undergoing considerable turnover on defense in a short time span.

“We had a bunch of new starters,” Austin said. “It was eight or nine. It was quite a few.”

Austin won’t have that many new faces to break into the starting lineup this season, his second as the Steelers defensive coordinator. Austin, though, is faced with overseeing the most changes to a Steelers defense since his arrival to the organization in 2019.

Depending on the package, the Steelers could have half a dozen starters on the field for the Sept. 10 season opener against San Francisco who weren’t around in January when the 2022 season concluded against Cleveland.

Cornerback Cameron Sutton, inside linebacker Robert Spillane and strong safety Terrell Edmunds left in free agency. Inside linebacker Myles Jack, slot corner Arthur Maulet and rotational nose tackle Tyson Alualu are gone, too. So is Devin Bush, who lost his job at inside linebacker to rookie Mark Robinson late in the season.

In free agency, the Steelers brought in inside linebackers Elandon Roberts and Cole Holcomb, nose tackle Breiden Fehoko, cornerback Patrick Peterson, safety Keanu Neal and slot corner Chandon Sullivan. The draft produced second-rounders Joey Porter Jr. at corner and Keeanu Benton on the defensive line.

It’s easier to count the returning starters on Austin’s unit: defensive linemen Cameron Heyward and Larry Ogunjobi, outside linebackers T.J. Watt and Alex Highsmith and free safety Minkah Fitzpatrick. Cornerback Levi Wallace, nose tackle Montravius Adams and strong safety Damontae Kazee also could return to starting roles they served for portions of the 2022 season.

“The key is, guys love football, and they come in and figure how to work better,” Austin said Tuesday on the first day of mandatory minicamp. “There is no magic formula. It’s guys coming in to work and trying to understand each other. At the end of the day, football is football. You can’t make it more than it is.”

The newcomers and the holdovers from Austin’s 2022 defense, which ranked No. 13 in the league, began assimilating last month at organized team activities. Although attendance at OTAs was optional, most veterans on the defensive side took part in many of the nine sessions.

“We’ve gotten good participation from guys,” Austin said. “It gives us a chance to learn about them, they learn about us, and it smooths the transition. It’s been good. … The guys we’ve added seem to be smart football players, which helps. They are good communicators. They have veterans to try to smooth it over, show how we do things here.”

Austin also will have a few weeks of training camp at Saint Vincent College and three preseason games to help define roles for the new additions to his defense. He welcomes the early start the players got at the optional workouts.

“How do you make it better? You have to be here,” he said. “Those guys being here helped. I get a chance to know them, so that first time you see them and get to know them is not under a stressful situation. Sometimes, those things can go a little sideways.

“Now, I get a chance to build relationships with them. They know me, they know the other guys, and that is important.”

Once Holcomb recovers completely from a foot injury, he and Roberts will form a new inside linebacker tandem. Austin said that will give Robinson, a converted running back, another year to develop.

“They have a little different skill set,” Austin said. “ ‘E’ is a first- and second-down thumper type of guy. Cole may give you a little more flexibility to play every down. We like that because we know they’ve started in the NFL. We know they are capable starters.”

On passing downs, the Steelers could have three new starters in the secondary: Peterson or Porter at outside corner, Neal at strong safety and Sullivan or Peterson at slot corner. That number could be four if Porter unseats Wallace at the other outside corner spot.

“That is still a work in progress,” Austin said. “Until we get into camp and get it going, it’s going to be a work in progress. The early returns, I like the collective maturity and intelligence of the secondary even with the young guys.”

Joe Rutter is a Tribune-Review staff writer. You can contact Joe by email at jrutter@triblive.com or via Twitter .