The Redskins can apply the franchise tag to Kirk Cousins beginning today should they choose to do so. (Mark Tenally, Associated Press)

With the NFL’s franchise and transition tag window beginning Tuesday, the waiting game now begins for Kirk Cousins.

The Washington Redskins have until the March 6 designation period to apply either tag to Cousins to prevent the 29-year-old quarterback from hitting free agency next month. And while the first day of the tag window came and went in Ashburn, tagging Cousins remains an option for team President Bruce Allen for another two weeks. However, choosing to do so would raise questions about the organization’s intentions and financial flexibility this offseason.

There has been speculation Allen strongly is considering tag-and-trade scenarios involving Cousins, going so far as to ask other team executives for their input. However, such a move could end up complicating the Redskins’ free agency spending.

Franchise-tagging Cousins for a third straight season would ensure that he doesn’t become an unrestricted free agent when the new league year begins at 4 p.m. on March 14, but it also guarantees him $34.5 million salary in 2018, from the Redskins or another team.

If Washington chooses to transition tag Cousins, the team has the right of first refusal should he agree to terms with another suitor. The Redskins would have seven days to match the other team’s offer sheet but would receive no compensation (except for a compensatory selection in the 2019 draft) if they decline. Unlike the franchise tag amount, Cousins would earn $28.78 million this season under the transition tag.

In May, Allen told reporters the Redskins are willing to use the franchise or transition tag on Cousins for a third time, saying, “In the collective bargaining agreement, we really have one year and an option that we can do at the end of next season if we don’t get a contract.” But that statement was made long before the organization chose to trade cornerback Kendall Fuller and a 2018 draft pick to the Kansas City Chiefs in exchange for quarterback Alex Smith.

Tags are purportedly used to keep a player in-house in hopes of reaching an agreement on a long-term deal. However, the Redskins already know who will be under center this season — and it isn’t Cousins. The terms of the Smith trade become official next month: a four-year deal (tacked on to his one remaining year under his Chiefs contract) that includes $71 million guaranteed.

Kirk Cousins will file grievance with players’ union if Redskins use franchise tag on him

According to a person familiar with his thinking, Cousins will file a grievance with the players’ union if he’s franchise-tagged because it’d be obvious the organization never intended to engage in good-faith negotiations on a long-term deal or have him play under the predetermined tag amount. Essentially, Washington’s sole motivation for tagging the quarterback would be to work out a trade with another club to recoup compensation. And Cousins’s camp could argue that strategy violates the terms of the collective bargaining agreement.

The potential return for the Redskins in a tag-and-trade scenario could be a draft pick or two, but they also risk giving Cousins the ability to hamstring the process if he doesn’t sign the tender. Until he signs it, Washington can’t trade him — and his astronomical tag amount goes on the Redskins’ books as soon as the league year begins.

Washington, which has a host of roster holes and pending free agents to tend to, has $48 million in salary cap space.

No one believes Cousins, who completed 64.3 percent of his passes and threw for 4,093 yards, 27 touchdowns and 13 interceptions last season, will be back in burgundy and gold for the 2018 season. Heading into the offseason, he was projected to make roughly $30 million a year on his next deal. And if he does hit the open market, as many expect, Cousins will have plenty of suitors.

The New York Jets, a team that has been desperate for a franchise quarterback for over a decade, reportedly want Cousins “badly” and are “willing to pay whatever it takes” to lure him to Florham Park, N.J. But even though the Jets have $73 million in available salary cap, the Denver Broncos have also emerged as a favorite to land Cousins. And, according to Redskins safety D.J. Swearinger, Cousins is the missing piece for the Broncos.

“With the situation they have out there on defense, they’re missing their quarterback,” Swearinger said Monday on NFL Network, referring to a unit that is headlined by elite pass rusher Von Miller. “Kirk is a great quarterback. I wish we could have had different things on that, but the business is the business. I think Kirk will be getting a healthy payday, and I think Denver is the team that can do that.”

Read more from The Post:

Kirk Cousins will file grievance through players’ union if Redskins use franchise tag on him

‘I remembered her’: During trip to Israel, Josh Norman reunites with one of his biggest fans

‘We all knew’: Devin McCourty speaks, but Malcolm Butler’s benching remains mysterious

Major Olympic wardrobe malfunction strikes during French ice dancers’ short program