Cousins underwent an MRI exam on Monday that confirmed the team’s initial fear about his first career injury, suffered when he planted his foot in the grass to step forward in the pocket and try to avoid a sack in the fourth quarter at Green Bay. Cousins went down in pain, had to limp off the field without putting weight on his right leg and was resigned to cheering on his teammates from a cart before the dreaded ride inside for further examination.

“We’re all hurting for Kirk,” Vikings coach Kevin O’Connell said, “just knowing how much he’s invested into this team.”

The Vikings (4-4) beat the Packers 24-10 on Sunday and climbed above the cut for the playoffs after an 0-3 start. Staying there will be far more challenging without Cousins, their ever-ready leader who’s suddenly and stunningly unavailable to play.

“There’s no doubt about it. We’re going to miss him,” O’Connell said.

Cousins will have surgery on a to-be-determined date. No recovery timetable was announced, but it’s typically at least a six-month process for returning to full strength. New York Jets quarterback Aaron Rodgers has raised the long-shot possibility of returning yet this season from his torn left Achilles tendon, but he’s nearly two months ahead of Cousins on his rehab because he was hurt in the opener.

Rookie Jaren Hall, a fifth-round draft pick from BYU, took over for Cousins. O’Connell refused to commit to Hall as the long-term replacement, though the Vikings would be hard-pressed to start anyone else this week when they visit Atlanta. Nick Mullens, the primary backup, is on injured reserve with a lower back injury and must miss at least one more game. If the Vikings were to bring in a veteran free agent or acquire one in a trade, he’d only have five days to assimilate to the offense.

“You wouldn’t believe some of the things on my cell phone I’ve received over here in less than 24 hours,” O’Connell said with a smile. “It’s what’s going to be best for our ability to win football games, but also knowing we’ve been living in a world where we want to be as competitive as possible right now, while also understanding what we’re building, hopefully, for the future at the same time.”

Cousins, who is on track to be a free agent next spring, has never missed a game in the NFL to injury. He has gone to great lengths to keep himself as healthy as possible, realizing the car-crash nature of his position while trying to extend his career as long as he can.

His appearance on the Netflix documentary “Quarterback,” that shadowed him, Patrick Mahomes and Marcus Mariota throughout the 2022 season endeared him to a broader audience with the up-close look at his willingness to take those punishing hits for his team and work arduously each week to prepare his mind and body for the next game.

The beginning of the show started with him at home reading a children’s book about football to his youngest son, Turner. The opening lines of the book that Cousins read to his son included this foreboding passage: “An injury to the quarterback can sink a team’s entire season.”

The Vikings are about to find out if it will or not.

The NFL trade deadline is Tuesday, but with so many injuries to quarterbacks this year the market is thin. Colt McCoy, who was cut in training camp by Arizona and remains unsigned, played for O’Connell in Washington.

There’s Matt Ryan, the 2016 NFL MVP who is not currently playing but has not declared his retirement.

Mullens made eight starts for San Francisco in 2018 and eight more in 2020, but O’Connell didn’t make it sound certain he’d be healthy as soon as he’s eligible to return to the active roster.

“Is it a short-term only thing? Is it something that could be more long term? Is it something that truly is an upgrade versus just the sheer dealing with the reality of a tough situation right now?” O’Connell said. “That’s what we have to work through.”

The late-blooming overachiever who was an afterthought recruit at Michigan State and a fourth-round draft pick in 2012, Cousins became the full-time starter with Washington in his fourth season and signed an unprecedented fully guaranteed contract with Minnesota in 2018 after he hit the open market.

Cousins has had his well-publicized share of ups and downs, with only one career win in a playoff game, but even at age 35 he’s continued to ascend as a passer in O’Connell’s complicated system. His completion rate (69.5 percent) is the third best of his career and fifth in the league in 2023. He’s tied for the NFL lead in touchdown passes (18), second in passing yards (2,331) and third in passer rating (103.8).

Over the three games since superstar wide receiver Justin Jefferson was sidelined by a hamstring injury, Cousins went 79 for 107 (73.8%) for 833 yards and five touchdowns with four sacks and two turnovers.

“It breaks my heart. That guy is the leader of the team. He’s the heart and soul of the team,” Hall said.

Cousins has been more introspective than ever this season, acknowledging with more depth the amount of anguish he puts himself through with his perfectionist mentality to playing the position. He even said last week he hates re-watching successful plays on film because they’re not constructive enough.

“It’s why sometimes you feel like this game’s a grind, because you’re never really just going out there and shrugging your shoulders and playing careless. You’re playing with so much care that you’re always evaluating and critiquing, and that’s kind of the balance I’m trying to find,” Cousins said. “I’ll always be trying to find, ‘How do you push yourself to be a better quarterback, which keeps you in this league and playing well, and then how do you still enjoy it and just kind of have fun and go play?’”