Seven Vikings starters or key contributors did not practice Sunday.

Wide receiver Stefon Diggs, safety Harrison Smith, cornerbacks Captain Munnerlyn and Marcus Sherels, middle linebacker Eric Kendricks and defensive tackle Sharrif Floyd stretched with the team inside the practice facility, then ducked out toward the locker room when drills began.

Center Joe Berger, who has a concussion, was not spotted at all.

But hey, at least right tackle Jeremiah Sirles practiced in some capacity after a hip injury knocked him out of Thursday's loss in Detroit.

Injuries along the offensive line have hit the Vikings hard, especially at offensive tackle. Three linemen are on injured reserve, and another, Mike Harris, remains on the non-football illness list and is out indefinitely.

Overall, the Vikings have placed nine players on injured reserve, which is not abnormally high at this point in a season. The Chicago Bears, for example, already have lost 14 players to season-ending injuries.

Still, coach Mike Zimmer said Sunday that this offseason the Vikings will look for answers on why their players have suffered so many injuries.

"We're going to sit down and look at everything," Zimmer said. "We're going to look at why guys got hurt, how they got hurt, where they got hurt. But at this point, it's just football things. We've obviously tried to put our finger on a lot of that. But we're not getting guys hurt in the weight room. Most every one of them has been on the field."

Berger is one of several Vikings who have suffered concussions this season. Zimmer was asked if there have been more of them recently or is it just that the number of diagnosed and reported concussions has risen in the NFL.

"I don't know. I'm old-school. Back in the old days, we didn't have any of that, I guess," the 60-year-old said. "I don't know. I couldn't tell you."

Another look

Quarterback Sam Bradford has had a chance to watch the film of his costly interception in the final minute of the 16-13 loss to the Lions.

On that play, Bradford targeted wide receiver Adam Thielen, who ran an out route out of the slot. Lions cornerback Darius Slay was on the outside, lined up across from rookie Laquon Treadwell, who ran a go route. But Slay pulled off of Treadwell and was in perfect position for the pick.

Three days later, Bradford was asked if in hindsight he would do anything differently on that play, which allowed the Lions to kick the game-winner.

"It's tough. They guy made a really good play," the quarterback said Sunday. "They trapped it. It was something we hadn't seen, and you'd like to be able to look out there and see him. But he turned his back with our outside receiver, really sold that he was going with him. If anything, [I would] try to peek out there and see him, but it was just a tough one to see."

Heart of the Cowboys

Zimmer spent a sizable chunk of his Sunday press conference praising the Dallas Cowboys, whom the Vikings host Thursday. The highest praise came when he was asked about a dominant Dallas offensive line.

With that group, standout rookie Dak Prescott has been sacked only 15 times in 11 starts and rookie Ezekiel Elliott has rushed for a league-leading 1,199 rushing yards.

"They're really good. They're really, really good," Zimmer said. "They're the best line I've seen in a long time in the NFL — physical, athletic, big."

Greenway: Don't write us off

The Vikings have lost five of their past six games to fall outside of playoff position in the NFC. But outside linebacker Chad Greenway said the 2012 Vikings are proof that it is premature to write off the 2016 Vikings.

"We were 6-6 in 2012 and won four in a row and made the playoffs, and I don't know if anyone wanted to play us. With [QB Christian] Ponder getting hurt, it really threw us through a loop," he said. "But we were playing as well as anybody and I think we can reference that team a lot."