It's hard to improve on the performance the Pittsburgh Steelers defense put together last season. As a unit, the defense finished fifth in the NFL in yards allowed (304.1) and points per game allowed (18.9). The group also led the league in takeaways with 38.

The Steelers' defense enters the 2020 season down two starters, but they can still be the same or better than a year ago thanks to the return of another starter from injury and more time in the system for newer defensive starters.

And, with the coronavirus pandemic causing an altered offseason and preseason, the Steelers' continuity on defense will be a significant advantage in 2020. After sizing up the offense last week, let's look at the outlook for the defense going into this season.

Defensive line

Additions: Carlos Davis (seventh-round pick), Chris Wormley (trade with Baltimore), Cavon Walker (XFL), Dewayne Hendrix (XFL), Josiah Coatney (undrafted free agent), Calvin Taylor (undrafted free agent)

Losses: Javon Hargrave (Eagles)

Retuners: Cameron Heyward, Stephon Tuitt, Tyson Alualu, Isaiah Buggs, Dan McCullers, Henry Mondeaux

Better, worse or the same? Same

Yes, the Steelers have to cope with the big loss of Hargrave. That shouldn't go unnoticed, and it will undoubtedly affect the defensive line. But they will get a boost from the return of Tuitt, who was on pace for his best season when he tore his pectoral muscle against the Chargers in Week 6 and finished the year on IR. Before the injury, Tuitt had 3.5 sacks, and if he can return to that form, he'll complement Pro Bowl defensive end Heyward.

The Steelers have a couple of options at nose tackle, but all are downgrades from Hargrave, who played himself into a significant contract with the Eagles after a four-sack, 60-tackle season. Like on the offensive line, coach Mike Tomlin will begin the replacement search with veterans because of the unconventional offseason. Alualu, a seven-year NFL veteran who played 40% of defensive snaps last season, will get the first shot at nose guard.

"Tyson's a veteran football player that's been here, that knows how to play the game," Tomlin said. "He and Dan [McCullers] are probably going to start, but he will probably take the first snap based on the things that I talked about relative to current circumstances. Then we will go from there.

"We are going to have a hardcore plan but be light on our feet and plan to adjust based on what it is that we see."

Linebackers

Additions: Alex Highsmith (third-round pick), John Houston (undrafted free agent), Christian Kuntz (XFL), Leo Lewis (undrafted free agent), James Lockhart (undrafted free agent)

Losses: Mark Barron, Tyler Matakevich (Bills), Anthony Chickillo (Saints)

Returners: T.J. Watt, Bud Dupree, Devin Bush, Vince Williams, Ulysees Gilbert III, Robert Spillane, Olasunkanmi Adeniyi, Tuzar Skipper

Better, worse or the same? Same

It's hard to improve on the job done by the Steelers' linebackers last season. The tandem of Dupree and Watt combined for 26 sacks, and after the team franchise-tagged Dupree, the duo will be back together in 2020. If Dupree can stay healthy another season, he and Watt will continue to be the cornerstone of the stout defense. The Steelers also added OLB Highsmith in the draft, but he'll likely see limited snaps behind Dupree and Watt.

Despite releasing Barron, the Steelers didn't add an inside linebacker in free agency or the draft. With his departure, the Steelers are pretty thin at the position. Bush played 82% of snaps last season, and he said earlier this summer he's prepared to play even more if necessary. He and Williams likely will see the most playing time, but the Steelers have potential depth in Gilbert, a 2019 sixth-round pick, and Spillane.

"It is up to Ulysees to get on the field," Bush said in May. "I think he is a really good player. He is really talented. I think he has all the intangibles, all the athleticism to get out there and play. It is up to him to put it all together. If it comes down to me and Vince taking all the reps, then I don't think we have a problem doing that."

Still, the inside linebacker group is one of the thinnest positions on the team with a small margin for error.

Cornerbacks

Additions: Breon Borders (XFL), Trajan Bandy (undrafted free agent), James Pierre (undrafted free agent) Arrion Springs (XFL)

Losses: Artie Burns (Bears)

Returners: Joe Haden, Steven Nelson, Mike Hilton, Cameron Sutton, Justin Layne, Alexander Myres

Better, worse or the same? Better

With five interceptions and one forced fumble and recovery last season, Pro Bowler Haden got most of the attention in the cornerbacks group. But Nelson was pretty solid, too, and didn't allow a touchdown catch. With a second offseason in Pittsburgh under his belt, Nelson, who had one interception and a fumble recovery in his first year with the Steelers, likely won't be flying under the radar for much longer. And the group has a chance to be even better than last season.

"Joe is my guy," Nelson said in June. "We are like Batman and Robin. Ever since I got to Pittsburgh, he has always been a very genuine guy just all around, on and off the field. I think we bounce off each other. We are both highly competitive guys. We feed off each other on the field. If he makes a play, I feel like I have to make a play. I feel like we pair together very well."

In addition to bringing back the position's headliners, the Steelers also return Hilton, the starting nickel who appeared in 62% of defensive snaps last season, and versatile backup Sutton. After only losing Burns, who played just 6% of defensive snaps last season, the corners are the most complete defensive position group entering 2020.

Safeties

Additions: Antoine Brooks Jr. (sixth-round pick), Tyree Kinnel (XFL), John Battle (undrafted free agent)

Losses: Sean Davis (Washington)

Returners: Minkah Fitzpatrick, Terrell Edmunds, Jordan Dangerfield, Marcus Allen

Better, worse or the same? Better

The Steelers lack depth at safety, but the position group will be better in 2020 for one reason: Fitzpatrick. Acquired by sending a first-round pick to Miami early last season, the Steelers got a ton of production out of Fitzpatrick in his first abbreviated season in Pittsburgh. But they're just scratching the surface of what he can do. As a free safety, Fitzpatrick had five interceptions last season, all coming in the first six weeks of his arrival in Pittsburgh.

"I think teams started to take less shots downfield or less shots where I was," Fitzpatrick said. "If I was in the half, there weren't going to be targets in that area where I was. I don't know if it was part of a game plan or the makeup of the quarterback, but I did realize a difference."

To prevent the same drop-off this season, Fitzpatrick wants to be more versatile in the defense -- something he'll be more capable of doing after an offseason of further learning the Steelers' system. Ironically, one of the reasons he wanted out of Miami was to focus on one position.

"If the coaches want me to move around, I'll move around," Fitzpatrick said in May. "If they don't, then I don't need to. I wouldn't say it's a goal. If they need me to move around, I'll learn the system and get it down to a ‘T' just in case I have to or if they ask me to move."

That could mean using different packages with Edmunds, who returns as the starting strong safety, or with rookie Brooks Jr., who has the size (5-foot-11, 210 pounds) of a hybrid safety-linebacker.