The Vikings’ sack party Sunday was a lesson for Dolphins quarterback Ryan Tannehill: These Vikings can get home with a blitz, which landed five of the nine sacks, or with a four-man rush that netted the other four on Tannehill.

But especially effective were those blitzes dialed up by coach Mike Zimmer. Tannehill faced the extra rush eight times. He threw three incompletions and took five sacks, including one by cornerback Mackensie Alexander.

“Well, he should [like blitzing],” Zimmer said Monday of Alexander. “He doesn’t get blocked.”

Zimmer had fun Monday with the notion that Alexander’s four sacks this season tied the Vikings’ single-season record for sacks by a defensive back, set by Robert Griffith in 1999.

“Somebody told me he set a record or something, but heck if you don’t get blocked,” Zimmer said, “he should have an asterisk by that.”

The Vikings’ blitz success came from proper timing of both the play call and rush, which was often hidden well before the snap by the likes of Alexander and linebacker Anthony Barr.

Zimmer took credit when it worked and blame when it didn’t. The Dolphins’ 75-yard touchdown run in the third quarter happened on the opposite side of an overloaded blitz call by Zimmer.

The third-year Alexander celebrated his sack by hitting a home-run ball, paying homage to nose tackle Linval Joseph, whom Alexander called one of his role models on the team.

“Watching the way he plays each and every week, way he practices,” Alexander said. “I actually stole that from him. He don’t know it. But hey he doing it, so I’m trying to do it as big as he’s doing it.”

No. 5 seed in play

The NFC wild-card playoff picture became even more clouded in Week 15. An upset of the Seahawks (8-6) and an upset by the Eagles (7-7) pinned two additional scenarios as plausible for the Vikings’ playoff fate.

The first is the Vikings (7-6-1) leapfrogging the Seahawks for the No. 5 seed, with Seattle preparing to host Kansas City this weekend and Minnesota having a favorable trip to Detroit. That could send the Vikings to Dallas, where the Cowboys (8-6) hold a one-game NFC East lead and tiebreakers over Philadelphia and Washington.

The second is the Vikings at No. 5 but traveling to Washington or Philadelphia, where the Redskins and Eagles are somehow not eliminated from a division title. If the Cowboys lose out (vs. Tampa Bay, at N.Y. Giants) and either the Eagles or Redskins win out (they play each other Week 17), either could host the Vikings in January.

For the record books

On Sunday against the Dolphins, receivers Stefon Diggs and Adam Thielen became the first Vikings duo to each catch 90 passes in the same season. The pair also became the first NFL teammates to do so this season.

“It’s cool,” Diggs said. “We’re still chipping away at a lot of stuff, but as far as getting wins and putting points on the board, it’s cool. Our running back is running crazy, our offensive line is blocking, our quarterback is balling, so I’m excited for the things to come.”

Fresh legs a focus

This Vikings team isn’t positioned to rest starters, but Zimmer said he’s been mindful of trying to maintain the defensive line’s legs late in these December games. Danielle Hunter (79 percent) and Joseph (57 percent) played below their season-average playing rates Sunday while the defense dominated the Dolphins.

“I’m trying to get them fresh in the fourth quarter,” Zimmer said.