EAGAN, Minn. (AP) — Off to an 0-2 start while trying to acclimate several new pieces into Mike Zimmer’s defense, the Minnesota Vikings suffered another big blow on Monday.

Four-time Pro Bowl linebacker Anthony Barr will miss the remainder of the season because of a torn pectoral muscle sustained in Minnesota’s 28-11 loss at Indianapolis a day earlier. Barr was placed on injured reserve on Monday.

“Anthony was our first draft pick that we’ve had when we came here,” Zimmer said. “A big, integral part of the defense. Good leader, great guy. It’s tearing him up inside that he’s not going to be able to play but … we’ve got to move on.”

The Vikings have started 0-2 for the first time with Zimmer as coach. The defense — Zimmer’s calling card — has struggled to stop the Colts and Green Bay Packers, while the offense has been unable to sustain any momentum.

Minnesota has allowed 35.5 points and 438 yards per game, the second- and fourth-highest totals in the league, respectively, through the first two weeks. The Vikings were fifth best in scoring defense and 14th in yards allowed last year.

Under Zimmer, Minnesota has never finished lower than 14th in either category and has had a top-10 unit the previous five years in points allowed.

“Defensively, trying to get these guys to understand the responsibilities and then play fast,” Zimmer said about incorporating young players. “Sometimes, it takes a little while. I do think we played better defensively yesterday. We had some good sudden changes, some good goal-line, red-zone defense situations. But we also didn’t make enough plays to help win the game.”

Barr, who has never missed more than four games in a season, was a leader on a defense that started Sunday without seven key contributors from last season. Trying to rebuild on the fly has proven more complicated than expected, and now the Vikings will be doing so without Barr.

Minnesota is left with 2019 All-Pro Eric Kendricks and Eric Wilson as starters at linebacker. Rookie Troy Dye, a fourth-round pick, replaced Barr and played 21 snaps in Sunday’s loss.

“I thought Troy came in and did some good things,” Zimmer said. “He had a couple missed tackles but he ran pretty well. Once Barr went out, it got a little confusing because Eric was trying to get the calls from the headset and then make the calls and get guys lined up. So that got a little confusing. Wilson did fine. We’ve still got a lot of things we have to work on with those guys, but we anticipate that they’ll continue to get better.”

What’s working

Perhaps Minnesota can take something away from its offensive success near the goal line. With running back Dalvin Cook leading the way, the Vikings are 4 for 4 on 2-point conversation plays and have scored three touchdowns in four chances in goal-to-go situations.

Cook has rushed for three touchdowns and three of the 2-point conversions, with Kirk Cousins passing to Adam Thielen for the other.

What needs help

One big loss from last season has proven to be tackle Linval Joseph in the middle of the defensive line. Joseph was released as a salary cap casualty. Michael Pierce was signed to replace Joseph, but he has opted out of this season because of the coronavirus.

Without Joseph or Pierce to clog the middle, Minnesota has allowed 154.5 rushing yards per game.

Stock up

The Vikings traded for Yannick Ngakoue to replace Everson Griffen at defensive end. After a tough first game in Minnesota, Ngakoue had a strip-sack of Philip Rivers on Sunday.

The Vikings will need more impact from Ngakoue, especially until Danielle Hunter can return from injured reserve with his reported neck injury.

Stock down

Cousins had the worst game of his career with a 15.9 quarterback rating. Sunday marked just the fourth time in 99 career games, including four in the playoffs, when he threw more than two interceptions. It was the first time he’s done so with Minnesota.

Injured

Dantzler was inactive on Sunday with a rib injury. Barr joins Hunter and starting right guard Pat Elflein on injured reserve.

Key number

20:10 – Struggling on both sides of the ball has led to an NFL-low 20:10 time of possession for Minnesota. It’s more than three minutes fewer than the next-closest team, the New York Jets at 23:15.

Next steps

Can the rebuild accelerate with the young players getting more snaps? Can they develop quick enough for it to matter this season? The next test will be another tough one with 2-0 Tennessee with running back Derrick Henry and quarterback Ryan Tannehill coming to Minnesota on Sunday.