When looking back with 20/20 hindsight, the scenario should have set off warning signs. Gone from the 2019 Gophers defense were four NFL draftees, including do-everything All-America safety Antoine Winfield Jr., plus a couple of other three-year starters. The coronavirus pandemic forced the Gophers to have only one practice in full pads last spring and shortened the length of fall training camp, robbing important development time.

The early results showed the impact, with the Gophers allowing 481 yards of offense in a 49-24 season-opening loss to Michigan, followed by a ghastly 675 yards and more than 10 yards per play given up at Maryland in a 45-44 overtime defeat.

"When guys are out doing it for the first time and then maybe robbed a little bit of the preparation, there's a fine line between playing bad defense and playing really good defense," said Gophers defensive coordinator Joe Rossi, who'll gauge how his defense has improved on Saturday morning in the Gophers spring game at TCF Bank Stadium.

Indeed, Rossi saw positive steps late last season as the Gophers (3-4) closed with a 24-17 win at Nebraska and a 20-17 overtime loss to visiting Wisconsin, games in which Minnesota gave up 308 and 322 yards, respectively.

In the offseason, the unit was bolstered by reinforcements in the form of three transfers: linebacker Jack Gibbens, a three-year starter at FCS-level Abilene Christian; and defensive linemen Nyles Pinckney, who spent the past five seasons at Clemson, and Val Martin, who played the past three seasons at North Carolina State.

Rossi knows a lot about getting a defense turned around. In 2018, he replaced the fired Robb Smith as coordinator after the Gophers allowed 646 yards, including 430 rushing, in a 55-21 loss at Illinois. The rest of that season, the Gophers went 3-1, averaging only 11.7 points allowed in victories over Purdue, Wisconsin and Georgia Tech.

"Even when it was the worst days of our defense last year, it was like, 'Hey, it might not be where it needs to be right now, but it's going to be something with this group,' " Rossi said. "They kept their head down, they worked, and they got better."

The influx of talent from the trio of transfers should help, starting with Gibbens, a 6-4, 240-pounder who had 258 tackles, including 22.5 for loss and seven sacks, along with five interceptions in four seasons at Abilene Christian. The Wildcats played Virginia last November, and Rossi saw on film that Gibbens could play at the next level.

"He's shown me he's everything we've expected, and maybe even a little more," Rossi said. "No. 1, he's a great human being. No. 2, he's super smart — a 4.0 undergrad. He's big. … And he can run. He's definitely added to the group."

When the Gophers recruiting staff forwarded Gibbens' name, Rossi became intrigued. Then coach P.J. Fleck was quickly sold. "We sicced Coach on him, and he was like, 'I want him! … Let's offer him. Let's go,' " Rossi said. "He committed 24 hours later."

Fleck is impressed with Gibbens' mental approach and how it's helping fellow linebacker Mariano Sori-Marin.

"A smart player is a better player. He can process information really quickly, he's learned our entire defense, he's responded really well," Fleck said. "There's a big difference between working hard and competing, and he competes every single play. That rubs off on everybody else. His leadership, the way he plays is infectious. Him and Mariano are kind of connected at the hip."

In the 6-1, 290-pound Pinckney and the 6-1, 300-pound Martin, the Gophers have a pair of additions that will add depth and talent to the defensive line. Pinckney played 55 games with 15 starts for Clemson, collecting 98 tackles (13.5 for loss), three sacks and three fumble recoveries. Martin had 29 tackles in 22 games at N.C. State.

"They've played a lot of football and had a lot of success," Rossi said. "The thing I like is they have different skill sets, and that's a good thing. … Val is a guy who has some twitch to him, some pass-rush to him. And Nyles has played at a super-high level in terms of the games he's been in throughout his career. He's got a little bit more girth to him, a little bit more strength."

Rossi is eager to see how this revamped unit will respond.

"We have a crack on the shoulder in terms of like, 'Hey, we know that it wasn't where it needed to be,' " he said. "It's motivation to work hard and change that."