Quarterback Kirk Cousins — he of that fully guaranteed $84 million contract — returns to MetLife Stadium on Sunday, to face the Giants.

Cousins played there last year, too, when the Vikings beat the Jets. But even if Cousins torches the Giants’ flawed defense to win his second straight game at MetLife Stadium, the reality remains: The Jets should be thrilled they weren’t able to sign him last year.

As you’ll recall, he turned down a three-year, $90 million contract offer from the Jets, and instead signed with Minnesota for $6 million less. The Vikings thought Cousins could boost them from contender to champion. But here in the second season of his contract, that hasn’t happened. Minnesota is 10-9-1 with Cousins as its quarterback, including 2-2 this year.

Cousins, who turned 31 in August, was always going to be a win-now signing for any team last year. The 2018 Jets clearly weren’t a win-now team.

And three games into the Adam Gase era, it’s clear now that they have many problems that signing Cousins would not have fixed. In fact, it would have limited the Jets’ ability to plug those roster holes, because they would’ve been committing $90 million to Cousins.

The Jets, 0-3 as they prepare to visit the Eagles on Sunday, have major issues on their offensive line, after neglecting the position group in the draft for years. They still don’t have a disruptive enough pass rusher. And their cornerback group is a mess, largely because Trumaine Johnson has failed to live up to his lucrative contract.

All of those things still would’ve been problems if Cousins was the Jets’ quarterback. They still would’ve limited the Jets’ ability to win games.

Would the 2018 Jets have performed better with Cousins than the 4-12 record they attained with rookie quarterback Sam Darnold? Probably, yes. But Cousins alone wasn’t turning that roster into a playoff team — and that’s the only thing you’re looking for when you give a 30-year-old quarterback $90 million. (The Vikings missed the playoffs last year, by the way.)

The Jets should consider themselves fortunate that Cousins spurned them, which led to them trading up in the draft to pick Darnold. Yes, the jury is still out on Darnold, who has played just 14 NFL games. But Darnold’s contract — $30 million over four years — gives the Jets a lot more flexibility to fix their roster.

That’s not to say new general manager Joe Douglas will patch things up any better than Mike Maccagnan, who did a mostly horrible job, particularly in the draft’s critical middle rounds. But at least Douglas isn’t hamstrung by a contract worth three times as much as Darnold’s.

The Jets are unquestionably a fiasco right now — 1-12 in their past 13 games, and 14-37 since the start of 2016. And Cousins could very well get things together in 2019 and lead the Vikings deep into the playoffs. He certainly has the defense to do it.

But even for a ready-to-contend team like the Vikings, Cousins hasn’t proven to be that much of a difference maker. They still have three fewer wins with him than they did in the season before he arrived, when they went 13-3 and lost in the NFC Championship Game.

Cousins finished last year 10th in the NFL in quarterback rating. Through four games this year, he is 23rd. His total quarterback rating in 20 games with Minnesota (98.1) would put him 13th in the league this year. So while he has been very good at times, has he really played like an $84 million quarterback?

No, he hasn’t.

And considering what the Vikings have done — or, more accurately, haven’t done — since giving him all that money, you can only imagine how much of a disaster this would’ve been for the Jets, who are no strangers to disasters.

NFL analyst Darryl Slater may be reached at dslater@njadvancemedia.com. Follow him on Twitter @DarrylSlater. Find NJ.com Jets on Facebook.