Kirk Cousins became the first player in NFL history to sign a fully-guaranteed, multiyear contract when he put pen to paper to join the Vikings for $84 million over three years.

“It’s a great contract,” said Cousin’s agent, Mike McCartney.

Ya think? It’s a record guarantee by $23.5 million over suddenly poor Matthew Stafford.

But was Thursday’s fully-guaranteed signing a landmark event? One that transforms the way the NFL does business with players who have been crying out for fully-guaranteed, long-term contracts for years?

“We sure hope it does,” McCartney said. “It’s time for NFL players to have guaranteed contracts. We see it in basketball. We see it in baseball. But we haven’t seen it in football. It would be great if this was a game-changer and started a trend.”

But can a situation as rare as Cousins’ really start a trend? A quarterback of this caliber, still in his prime, reaching the open market before his 30th birthday is pretty much the NFL equivalent of spotting Bigfoot reeling in the Loch Ness Monster.

“The closest thing you could compare it to would be Drew Brees,” Vikings General Manager Rick Spielman said of Brees leaving the Chargers for the Saints in 2006. “And Brees was coming off [major] shoulder surgery.”

Former Vikings center Matt Birk called the contract “historic,” but tapped the brakes on it being a trendsetter or beyond the dollar amount the Vikings would have had to guarantee a player of Cousins’ caliber anyway.

“If he had signed a five- or six-year deal, you’re looking at the same guaranteed money,” Birk said. “I think it seems like a situation where it works for both parties.”

Birk created headlines in training camp in 2005 when he asked the Vikings to guarantee his contract terms for the 2006 season. He was in the fifth year of an eight-year deal when he was sidelined because of a sports hernia.

He and the team agreed that surgery was inevitable. When coach Mike Tice mentioned publicly that playing through the injury was a matter of pain tolerance and wouldn’t worsen Birk’s condition, Birk said he’d put off surgery and try to play the season if the Vikings would guarantee his contract terms for the following season.

“I didn’t know if I’d be able to play, and I didn’t know how well I would be able to play,” Birk said. “They could have cut me after that year and I wouldn’t have had any leverage because I could have conceivably been coming off a subpar year.”

The Vikings declined. Birk had the surgery.

Birk, however, is not in favor of guaranteed contracts for NFL players.

“If that happened, the total value of contracts would go down mainly because of injuries,” Birk said. “And I don’t think our game would be as great as it is because it’s just human nature. If you know you’re getting paid no matter what, I think some guys won’t put forth the effort.

“There’s only so much money to go around. So if a guy signs a five-year, $100 million deal and gets lazy and doesn’t perform, that’s taking money away from guys who deserve it.”

McCartney, for obvious reasons, disagrees. And he wants to see the NFL and the players’ union do away with Article 26, Section 9 of the collective bargaining agreement. That’s the so-called “funding” rule that hinders fully-guaranteed deals by forcing teams to put all deferred guaranteed money in escrow.

“It’s seems to be an archaic rule that’s not necessary anymore,” McCartney said. “So getting rid of that is probably the next step.”

Cousins played through two years of franchise tags in Washington to reach Thursday’s historic moment. He seemed eager to put it behind him.

“It is what it is for my situation, but players after me are going to have to decide what they want to do,” Cousins said. “There’s nothing I can pave [the way for] unless other people come after me. History will probably write that more than right now.”

You can bet Aaron Rodgers and Matt Ryan are two guys who will benefit from Thursday’s signing. But neither Spielman, nor owner Mark Wilf, see Cousins’ contract changing the overall NFL landscape.

“I don’t know where it’s going to go,” Spielman said. “But I know when a player of this caliber gets out there on the market and he’s been franchised two years in a row, and it’s the quarterback position, you’re going to have to do what you have to do. If we didn’t, I know a lot of other teams out there would have.”