The defense ranks No. 1 in points allowed. The offense still hasn’t turned the ball over. Sam Bradford needed only four starts in purple to post the first four-game winning streak of his career. And when the cupboard was emptied of veteran offensive tackles, voilà, Jake Long showed up Tuesday looking healthy, hardy and happy to be the newest member of the NFL’s only undefeated team.

Before criticizing the Long signing for age, injury and/or financial purposes, beware. The past 39 days haven’t been kind to the amateurs who think they’re smarter at professional football than Vikings General Manager Rick Spielman.

Among the many other twists, wide receiver Cordarrelle Patterson is emerging as an offensive threat. Trae Waynes is rotating in as a viable member of the league’s deepest crop of cornerbacks. And the reason receiver and first-round draft pick Laquon Treadwell isn’t playing has a lot to do with the fact Spielman drafted Stefon Diggs in the fifth round in 2015 and unearthed an undrafted nobody named Adam Thielen during a rookie minicamp tryout in 2013.

In the past 43 days, Spielman has lost a franchise quarterback, made a risky, expensive but necessary trade for a franchise quarterback, won a game with Shaun Hill, and watched as injured reserve gobbled up a Hall of Fame running back, both starting offensive tackles and $33 million in salary cap space. And yet here he sits alongside coach Mike Zimmer and the 5-0 Vikings at the bye week.

Coming out of that bye, it’s entirely possible that Long will be protecting Bradford’s blind side as the Vikings attempt to go 6-0 for only the seventh time in 55 seasons. Even in a crazy, anything-goes league, that qualifies as one weird start to a season.

Forty-three days ago, the life was sucker-punched out of this team when Teddy Bridgewater’s left knee crumpled so badly that his return for the start of next season is in doubt. Four days later, Bradford arrived in a trade for next year’s first-round draft pick and a conditional fourth-rounder in 2018.

Some argued that Spielman overpaid and mortgaged the future, even though recent trades have given him ample draft capital in the second and third rounds to continue his trend of trading up into the first round for blue-chippers such as safety Harrison Smith. In reality, what Spielman did was take an executive-of-the-year-caliber risk for a Super Bowl contender, breathing life back into an entire franchise rather than tanking a year of everyone’s brief careers for a high draft pick in 2017.

That was Spielman’s blockbuster move. His record isn’t perfect, but he does have a number of smaller successful moves that he’s executed while he and Zimmer have learned the tricky art of synchronized personnel decisionmaking.

Look no further than the three-technique defensive tackle position for two under-the-radar moves that have rendered the loss of first-round draft pick Sharrif Floyd to a non-story during the best stretch of defense this franchise has played in decades.

When completely healthy, Floyd is a Pro Bowl-caliber player. But rarely is he completely healthy. He’s missed the past four games after yet another knee surgery.

No problem. In his place, the Vikings use two guys who brought no headlines or hoopla when Spielman acquired them in 2014. Tom Johnson, an interior pass rusher, arrived via free agency. Shamar Stephen, a big-body run stopper, was drafted 220th overall, 36 spots from the bottom of the seventh and final round.

The 32-year-old Johnson still has a quick burst in the pass rush, while the 25-year-old Stephen was singled out by Zimmer and Spielman as a difference-maker in explaining why the run defense has climbed to No. 10 in the league.

“They each have their strengths and weaknesses,” Spielman said. “When you can combine those two guys’ strengths together you have a pretty good one guy, if that makes sense, because of the way the coaches use these guys.”

Spielman has selected 10 seventh-­round draft picks that are now on NFL rosters or practice squads. That leads the league, according to the Vikings’ research. The Vikings have four of them on their active roster and one on their practice squad.

“Those seventh-round picks are extremely important,” Spielman said. “I always say in the draft class coming up, ‘Let’s try to beat out the last draft class.’ We’re always trying to get better than we currently have. Once you get satisfied and think you have everything, I think that’s when you get passed by.”