Kirk Cousins bolting Vikings to sign with Falcons on $180 million contract

Kirk Cousins might retire one day as the highest-paid player in NFL history.

Cousins reportedly agreed to terms Monday on a four-year, $180 million contract with the Falcons, leaving the Vikings in the biggest move made on the first day of free agency.

The 35-year-old quarterback was the No. 1-ranked player on The Post’s list of the top 30 free agents.

By adding $100 million guaranteed to his career earnings over 12 seasons with the Commanders and Vikings, Cousins now is assured of at least $331.6 million, according to spotrac.com.

Only the Jets’ Aaron Rodgers ($342.4 million) has earned more in his career, and Cousins could play longer than the 40-year-old Rodgers and surpass $400 million before Patrick Mahomes gets there on his 10-year, $450 million contract running through 2031.

Nine of the 10 highest-paid players in NFL history are Super Bowl-winning quarterbacks and the other is Matt Ryan, who led the Falcons to a Super Bowl in which they blew a 25-point second-half lead.

Cousins will try to finish the job for the franchise, but the knock throughout his career has been a lack of playoff success (1-3 record).

The Cousins master class on maximizing value began when he became the first quarterback ever to play on back-to-back franchise tags in 2016 and 2017 and continued when he signed a rare fully guaranteed three-year, $84 million free-agent contract with the Vikings.

What became a six-year relationship is over because the Vikings didn’t match what the Falcons — desperate to find a franchise quarterback for a win-now roster — were willing to offer.

“After significant and positive dialogue with Kirk and his representatives,” Vikings general manager Kwesi Adofo-Mensah said in a statement, “we were unable to reach agreement on a contract that fits the short- and long-term visions for both Kirk and the Minnesota Vikings.”

The Falcons jump to the top of a wide-open NFC South and into the mix of second-tier challengers to the 49ers in the NFC.

After a potentially fortuitous miss on trading for Deshaun Watson when he landed with the Browns in 2022, the Falcons mistakenly did not make an offer to Lamar Jackson when he was on the franchise tag and seeking a trade last offseason — before he signed a five-year, $260 million extension with the Ravens and went on to win his second NFL MVP.

There is a sense that an offense with three former first-round picks on the offensive line and three former first-round picks from the last three drafts — tight end Kyle Pitts, receiver Drake London and running back Bijan Robinson — is a quarterback away from taking off.

Newly hired head coach Raheem Morris, who coached on the defensive side of the ball when Cousins was in Washington, made no bones about replacing inherited starter Desmond Ridder from Day 1 on the job.

Cousins was having one of the best statistical seasons of his career (18 touchdowns, five interceptions, 291.4 passing yards per game) when he suffered a season-ending torn Achilles in the eighth game of last season.

The Vikings are left in dreaded quarterback purgatory at the wrong time.

Backup Josh Dobbs is a free agent, leaving third-stringer Nick Mullens and Jaren Hall — coming off a rookie season in which he did not play — atop the depth chart.

With Baker Mayfield (Buccaneers), Russell Wilson (Steelers) and Gardner Minshew (Raiders) off the free-agent board, the Vikings are expected to turn their attention to options like failed Jets and Panthers starter Sam Darnold.

One option that would’ve been a possibility for the Cousins-less Falcons — trading with the Bears for Justin Fields — seems unlikely for the Vikings because of their division rivalry with Chicago.

The Vikings hold the No. 11 pick in the draft and could feel renewed urgency to get in the trade-up market for one of the four quarterbacks — Caleb Williams, Drake Maye, Jayden Daniels and J.J. McCarthy — who widely are expected to be top-10 picks.

After all, All-Pro receiver Justin Jefferson is seeking an extension and likely is going to want to know who is throwing him passes in the future — even if a new contract makes him the highest-paid receiver in the NFL.