Typically after frustrating losses and then venting to reporters in their immediate aftermath, Vikings coach Mike Zimmer has mellowed out by the following afternoon, sometimes even backtracking after getting his point across in the postgame news conference.

But on Monday, about 24 hours after his Vikings defense fall apart at Sun Life Stadium in Miami, Zimmer still was steaming over what he said was the worst performance he has seen from his defense all season.

"Maybe one of the worst defensive performances I've seen in a long time," he added. "But definitely this year, for sure."

After taking a 17-7 lead into halftime against the Dolphins, the Vikings defense could not get a stop in the 37-35 loss. In the second half, it offered little resistance on four consecutive Dolphins touchdown drives, spanning a total of 304 yards.

In the final minute, the Dolphins could bust out the Victory formation after a blocked punt resulting in a safety decided the game. And even then it felt as if the Dolphins might somehow kneel their way into the Vikings end zone.

"He was livid," defensive tackle Sharrif Floyd said when asked what Zimmer had to say after the loss. "In his position, I would be, too, watching the defense do what we did. That was a disgrace for us as a unit. We got to do better."

Against a Vikings pass defense that entered the game ranked sixth in the NFL, Dolphins quarterback Ryan Tannehill completed 35 of 47 passes for 396 yards and four touchdowns. Five of his receivers had at least 50 receiving yards.

"I can't remember the last time I've given up 400 yards passing or if there ever has been one," Zimmer said.

Technically, accounting for the yards lost on two sacks, the Dolphins had 377 net passing yards. It was the most the Vikings have surrendered all season, and it also was the most net passing yards a Zimmer defense had allowed since his Cincinnati Bengals unit got picked apart for 385 in a 2009 loss to the Houston Texans.

Miami did significant damage on the ground, too. Led by running back Lamar Miller, the Dolphins rushed for 116 yards and their backs averaged 5 yards per carry. It was the 12th time this season that opponents reached triple digits in rushing yards against the Vikings.

Too often individuals ignored their assignments, and even subtleties such as poor pre-snap alignments popped up all over the place as Zimmer reviewed film of the game.

Plus, the Vikings defense failed in key situations, stopping the Dolphins only four times on third down and allowing them to score touchdowns on all five of their red-zone trips.

The defense also committed 12 penalties — including two personal fouls after the whistle — though not all of those penalties were accepted by the Dolphins.

"We didn't do anything right," Zimmer said.

So Zimmer let his players have it in the locker room after they gave up 23 fourth-quarter points — and another late lead — in the loss.

"He was upset," middle linebacker Jasper Brinkley said. "He should be. We gave up that fourth-quarter lead. There's no way that should have happened."

The Vikings had been making steady progress in Zimmer's first season as head coach. While their inability to smother running backs has been a continual concern, their pass rush and aggressive play in the secondary buoyed them.

The Vikings ranked 11th in the NFL in total defense entering Sunday, with a legitimate chance at cracking the top 10 by season's end. But then they allowed 493 total yards of offense against the Dolphins and 36 first downs.

"I don't know who they were Sunday," Zimmer said. "It's disappointing to me that, I mean we had guys who are normally good players that played poorly. I mean really poorly. That surprised me. Guys that you know you can count on that didn't play good, that's frustrating. I don't know. I don't know what it is."

As a result, the Vikings dropped to 15th in total defense, but Zimmer couldn't care less about that right now. He still is ticked off about how his defense, after months of progress, reverted to being a group of individuals instead of a formidable unit against the Dolphins.

"I will get this defense fixed," Zimmer vowed. "It may not be this week. It may not be until middle of [next] year. But it will get fixed. You can bet your butt on that."