This season that started with so much promise for the Minnesota Vikings has been slipping away.

Their margin for error, nearly flattened by an offensive line depleted almost beyond belief, has rendered moot most of their strides during the skid.

“We do a lot of good things but, unfortunately, the way our football team is right now we have to make sure we execute better in some of these critical situations in the ballgame,” coach Mike Zimmer said Friday, after the Vikings lost 16-13 at Detroit and fell behind the Lions and out of first place in the NFC North for the first time since Dec. 27, 2015.

The Vikings (6-5) have lost five of their last six games after posting the NFL’s only 5-0 start.

“All these games are going to come down to the wire, probably, the way we are,” Zimmer said. “We’re just going to have to tighten it up a little bit and keep moving on. There’s still a lot of football left, so we’re going to keep going.”

The Vikings led 13-10 at 2-minute warning on Thursday, but Matt Prater made two more field goals after that to lift the Lions to victory. This came just 18 days after Prater’s 58-yard kick as time in regulation expired put the Lions in position to win in overtime at Minnesota in the first matchup.

“It doesn’t feel good. Hopefully, we can play them again in the playoffs and just get another try,” wide receiver Adam Thielen said.

For the first time this year, the Vikings have found their postseason push in trouble. The Lions will have the tiebreaker for the division title, so they’ll need to win twice more than the Lions over the final five-game stretch to defend their NFC North crown and get the automatic home game. The wild card race remains wide open as well, with a critical tiebreaker edge for the Vikings over the New York Giants (7-3), but they’re playing catch-up there too.

“All we can do is worry about who we have next week, and that’s Dallas,” quarterback Sam Bradford said.

Gulp. The Cowboys (10-1) have won 10 straight games.

“I know what this team can do,” left guard Alex Boone said, when asked after the game what gives him belief in a rebound. “You know, I’ve seen this team play well against good teams.”

The biggest problem is that the Vikings have more than run out of reliable blockers around Boone on the offensive line. Already missing tackles Matt Kalil, Jake Long and Andre Smith for the season, plus Mike Harris, who has started at both guard and tackle for this team, the Vikings watched center Joe Berger get knocked out of the game with a concussion. Right tackle Jeremiah Sirles later hurt his left hip. Zimmer had no update on Friday on either player, but the way this team’s luck has been this season with health seeing both of them in the lineup against Dallas would almost be a surprise.

Rookie Willie Beavers replaced Sirles, and Nick Easton filled in for Berger.

“At some point we’ve got to catch a break,” tight end Kyle Rudolph said, adding: “You’re starting to get into a rhythm and another guy goes down. We can’t make excuses. Injuries are a part of this game. It’s just unfortunate.”

Singling out the inability to keep Matthew Stafford from escaping the pocket for first-down runs at a couple of critical points would be a bit unfair to a defense that’s allowing just 17.5 points per game, the second-lowest in the league.

Blaming the patchwork offensive line would be pointless, and it’s worth noting that Bradford’s quick release and offensive coordinator Pat Shurmur’s plan for short throws at Detroit led to the quarterback getting hit only three times.

But the reality is that the Vikings, even with a friendly final four games, have so many limitations now that making the playoffs would be quite the feat.

“Even when we were in the playoff mix, we didn’t ever talk about it,” Zimmer said. “We just talked about the next game, and that’s all we’re going to continue to talk about.”