WASHINGTON — It is all falling into place off the ice for the Rangers, who on Saturday took the required preliminary steps to clear enough cap space to accommodate the acquisition of Patrick Kane by waiving Jake Leschyshyn and trading Vitali Kravtsov to Vancouver for spare parts.

The savings through those two maneuvers should allow the Blueshirts to add Kane to the roster before their game Wednesday at Philadelphia, per CapFriendly, though they will have to do without Kane on Sunday when the Kings visit the Garden for an early evening start.

Indeed, it appears as if the Blueshirts will have to play a man short against Los Angeles in the aftermath of the left shoulder injury Ryan Lindgren sustained Saturday. Lindgren was injured during the first period of the Rangers’ 6-3 loss to the Capitals and had his arm in a sling as the club returned home.

Kane left the Blackhawks’ road trip in California to return home to Chicago, either to engage in final soul-searching before officially waiving his no-move clause or to get a jump on packing for what could be a four-month stay in New York.

Rangers general manager Chris Drury still has the responsibility of locating a third-team conduit to assume a quarter of Kane’s $10.5 million cap hit after the Blackhawks retain half. He still must complete the trade with Chicago in an environment in which Kane and the Rangers appear to hold substantial leverage, but the Blackhawks still have to sign off on the deal without feeling they have been taken advantage of.

But the trade seems more than just on track. It appears inevitable. More than 15 months after Kane was first attached to the Rangers in this space, it seems as if it is only a matter of days before he slips into the Blueshirt.

If it is by Wednesday, head coach Gerard Gallant will have 22 games with which to integrate Kane into the lineup. Vladimir Tarasenko is having a difficult enough time meshing with his teammates after eight games with the squad following his headlined Feb. 10 acquisition from the Blues.

Off the ice, the deal is on track, but on the ice, the Rangers are falling apart, a third consecutive uninspired and undisciplined performance resulting in a third consecutive regulation defeat and fourth straight defeat overall (0-3-1) following a seven-game winning streak that apparently seduced everyone into thinking everything was going to come easily.

“I think after that streak we think we can just show up and win games,” said Chris Kreider, who scored a third-period power-play goal after the match had blown open, but played as poorly as anyone. “We’re playing stubborn hockey.

“Playing against a team that played a 1-3-1, we refused to play simple hockey and just get it in and force the defense to turn and retrieve the puck. It starts with the veterans. It starts with me, I’m not someone who should be handling the puck in the neutral zone. It’s on me to get it in. I didn’t do that enough.”

The Rangers were negligent with and without the puck, yielding a massive number of odd-man rushes and breakaways. Goaltender Igor Shesterkin was yanked after allowing five goals on 22 shots in 40:00, which included four goals on 14 shots in the second period when the Capitals, losers of seven straight while outscored by an aggregate 24-10, bolted to a 5-1 lead.

Yet Shesterkin may have been his team’s best player. That’s how disorganized and delinquent an effort this became. All that was missing was Jacob Trouba throwing his helmet at the Rangers’ bench.

“Everybody hears the noise that’s going around, but that happens in one form or another every year. That can’t be an excuse for this. Players have the responsibility to play,” Trouba told The Post. “We have to be ready.

“Maybe the goals were coming kind of easy during our winning streak and we got the idea that’s how it was going to be. But it’s not easy. And we’re giving up way too many Grade-A looks against. We have been for a while.“We were getting away with it during that streak,” the captain said, “but it’s not a sustainable way to play. It’s not a sustainable way to win.”

The Blueshirts lost Lindgren at 8:11 of the first period after he was crunched hard into the wall by T.J. Oshie on a check that Gallant deemed, “a bad hit … dirty.” Ben Harpur, dressed as a seventh defenseman, took a regular turn, finishing with 15:50 of ice.

The defense was not particularly stout, but the backtracking and backchecking were nonexistent. The Rangers, who are in the midst of their second four-game losing streak (0-2-2 from Oct. 20-26) and second three-game regulation losing streak (Nov. 23-28) of the season, are disconnected.

That is understandable if one of them is at home in Chicago.

Hurry, Wednesday, hurry.