After Minnesota coach P.J. Fleck fired defensive coordinator Robb Smith midway through the 2018 Big Ten slate, his replacement brought with him an instant cohesion not seen in Gopher football.

The results from last season, Joe Rossi’s first full season as DC: No. 10 total defense in NCAA Division I and the No. 26 most efficient unit per ESPN’s SP+ analytics.

En route to the Gophers’ best season in more than 5 decades, Minnesota upended top-10 opponents Penn State and Auburn, holding the Tigers to just 232 yards in a 31-24 Outback Bowl victory Jan. 1.

Rossi did it with a lot of talent, including at least 1 2020 NFL Draft pick at each level of the defense. Can the development of those behind them pay off in a repeat performance?

There are certainly some sizable gaps to fill. Especially against an all-Big Ten schedule.

What should you expect this season? Let’s compare this 2020 defense to 2019.

Personnel: Worse

Key losses: Antoine Winfield Jr., S; Kamal Martin, LB; Carter Coughlin, DE; Chris Williamson, CB; Winston DeLattiboudere, DE; Tai’yon Devers, DE; Sam Renner, DT; Thomas Barber, LB

Key returnees: Micah Dew-Treadway, DT; Keonte Schad, DT; Mariano Sori-Marin, LB; Benjamin St-Juste, CB; Coney Durr, CB; Jordan Howden, S

Potential breakout players: Keonte Schad, DT; Esezi Otomewo, DE; Boye Mafe, DE; Braelen Oliver, LB; James Gordon, LB; Donald Willis, LB; Justus Harris, NB, Solomon Brown, NB

Minnesota’s ability to develop defensive talent was on display during this year’s NFL Draft as safety Antoine Winfield Jr., cornerback Chris Williamson, defensive end Carter Coughlin and linebacker Kamal Martin all heard their name called. The Gophers were further depleted in the front 7, losing defensive tackle Sam Renner and linebacker Thomas Barber to graduation..

The returning secondary is strong, led by cornerback Benjamin St-Juste and safety Jordan Howden, the team’s top returning tackler.

Minnesota doesn’t recruit classes that land in the top half of the Big Ten rankings. Fleck, Rossi and friends rely on building from within.

Their ability to do so will be greatly tested when, and if, the 2020 season takes place.

Pressuring QB: Worse

The Gophers got to the quarterback just 28 times last year. By comparison, Ohio State led the country with 54 sacks. Wisconsin was tied for 2nd with 51.

More than half of Minnesota’s sacks came from now-departed Renner, Coughlin, Winfield and defensive lineman Tai’yon Devers. Renner in particular was good at making plays that didn’t necessarily show up in the stats, disrupting opponents’ timing and taking on multiple blocks to his teammates’ benefit.

So it’ll be incumbent upon Dew-Treadway (13 tackles, 2.5 for loss last season), Otomewo and the Gophers’ wide-open linebacker position to harass Big Ten quarterbacks.

Run defense: Worse

The Gophers gave up 122.4 yards on the ground per game last season, which was 7th in the B1G. Rossi’s transition to a 4-man front — with one defensive tackle in a 3-technique, the other in a 1-technique — paved the way for Winfield, Martin and Barber to each tally 66 or more tackles.

All three are gone.

Keonte Schad is one of Minnesota’s best run-stuffers. The 2018 JUCO All-American could be in line for a breakout season.

Mariano Sori-Marin is the closest thing to a sure bet at linebacker. The secondary is full of reliable tacklers and, like last year, will be called upon to come up and make plays — especially in support of an inexperienced front 7.

Pass defense: Even

It’s hard for any facet to improve markedly when it loses a defensive back as decorated as Winfield. After netting All-American First-Team All-Big Ten and Tatum-Woodson (defensive back of the year) honors, the son of former NFL cornerback Antoine Winfield Sr. was drafted in the 2nd round by Tampa Bay.

The loss stings. Winfield led the team with 88 tackles and accounted for 7 of Minnesota’s 14 interceptions. But the Gophers return the rest of their starting secondary from a defense that ranked No. 2 in the Big Ten against the pass. Durr, frequently a top-rated cover man by Pro Football Focus, tied St Juste for the team lead in pass breakups with 10. Howden has played in all 26 games of his career and started 17.

But even experience can’t do it all without an effective pass rush. While the secondary will be a strength, it puts even more pressure on the Gophers’ up-and-coming linebackers and defensive linemen to do their part.

Special Teams: Even

Minnesota’s net punting total of 37.29 yards was well below average last season — 90th in Division I. The good news? Opponents gained just 1 — 1! — return yard against the Gophers all season.

Still, a more reliable leg would take the pressure off a defense looking to replace multiple key pieces. Mark Crawford and Matthew Stephenson were set to compete for the starting job in spring before COVID-19 upended the college football calendar.

Stephenson has 16 career punts for an average of 37 yards. Crawford joins the program after playing Australian Rules Football and cricket, then training at Prokick Australia, which has produced 5 Ray Guy Award winners.

Overall: Worse

A step back on defense doesn’t mean the Gophers won’t be formidable. Disciplined with a touch of nasty every year under Fleck, Minnesota won’t be an easy team to score against.

It just might not be quite as tough as it was in 2019.