Who knew how to react after Kirk Cousins and the Vikings tied the Packers on Sunday in Green Bay? (Joe Robbins/Getty Images)

When the NFL shortened overtime from 15 to 10 minutes for preseason and regular season games before last season, there were concerns that the move would result in more ties. It wasn’t exactly a complete freakout, but there was some fretting. This is, after all, the sport of, “You play to win the game,” as former coach Herm Edwards so famously said. Why spend more than three hours and go home without a winner?

Those reservations were not shared by the NFL rule-makers who proposed the change, nor by the owners who ratified it in May 2017. The move was made in the name of player safety. Members of the league’s competition committee didn’t want anyone to play what amounted to a five-quarter game Sunday, then come back a week later — or even less than that — and play again.

And besides, they figured, are ties such a terrible thing? They actually help when it comes to the tiebreakers for playoff spots. A 9-6-1 team clearly finishes ahead of a 9-7 team and clearly finishes behind a 10-6 team, for example, without everyone having to sort through head-to-head results and division records and conference records and so on.

The entire issue never came up last season. There were no ties at all last year, and the concerns faded. It was a crisis averted. But that was only temporary. Two weeks into the 2018 season, there already have been two ties, with the Pittsburgh Steelers and host Cleveland Browns playing to a 21-21 deadlock in Week 1, and the Minnesota Vikings and Green Bay Packers finishing in a 29-29 draw Sunday at Lambeau Field.

“It doesn’t feel good,” Packers linebacker Clay Matthews told reporters after the game. “It doesn’t feel like a win. It almost feels like a loss. And I’m sure they probably share that same belief in the Vikings’ locker room just because both teams had a number of opportunities to win this game. … It doesn’t feel good. But I guess it’s better than a loss, if you want to be Mr. Optimism.”

The freakout over ties can officially commence.

“Two weeks in the NFL and two ties,” former New England Patriots linebacker Tedy Bruschi, now an NFL analyst for ESPN, wrote on Twitter. “[Overtime] rules need to change. Pro football should have a winner and a loser.”

The NFL last had two ties in a season in 2016, when the Seattle Seahawks and Arizona Cardinals played to one draw and the Washington Redskins and Cincinnati Bengals to the other. This is the first time there has been a tie in each of the first two weeks since 1971, when there was a Week 1 deadlock between the Miami Dolphins and Denver Broncos and a Week 2 draw between the Atlanta Falcons and Los Angeles Rams.

The NFL put sudden-death overtime for regular season games into effect in 1974. There have not been more than two ties in any season since, according to Pro Football Reference. There were seven ties during the 1973 season, and there were nine during the 1970 season.

In 2012, the league modified the overtime format for the regular season to prevent a team from winning with a field goal on the opening possession. (The change had been made for postseason games two years earlier.) Under the change, a team can win with an opening-possession touchdown. If a team gets an opening-possession field goal, its opponent is given a possession with a chance to tie the score with a field goal or win with a touchdown. If the teams trade field goals, the game proceeds in sudden-death fashion.

That format, combined with the shortening of overtime, could be a recipe for more ties. If a team has a long opening possession and gets a field goal, for instance, its opponent might face a time crunch on its way to a potential winning touchdown and might have to settle for a field goal.

But this season’s ties have been based on kicking misadventures. Both kickers from the Week 1 tie, the Steelers’ Chris Boswell and the Browns’ Zane Gonzalez, missed potential game-winning overtime field goal attempts. On Sunday in Green Bay, Packers kicker Mason Crosby missed a field goal as time expired in regulation, and his Vikings counterpart, Daniel Carlson, missed on the final play of overtime.

The Vikings also had their drive to a touchdown and the tying two-point conversion late in regulation extended by a controversial roughing-the-passer penalty called on Matthews.

So it still takes a lot to bring about a tie in the NFL. But those crazy circumstances have come together twice in two weeks. And if they keep happening, the outcry is sure to get louder.

Read more NFL coverage from The Post:

The Patriots’ grip on the AFC is slipping, and the Jaguars are the ones prying it away

John Clayton: Five ways the Packers-Vikings tie embodies the start to this NFL season

Bills’ Vontae Davis retires at halftime of Sunday’s loss to the Chargers

The NFL belongs to Patrick Mahomes now