Barry Trotz has done a Mike Keenan.

He’s walked out on a Stanley Cup-winner; the club he cultivated from first round-almost-loser- to Champs.

Keenan did it to the Rangers in 1994, moving on to coach the Blues in St.Louis.

Now Trotz is the ex-coach of the Caps who can stop celebrating and mourn the departure of their leader to — where?

There are 31 teams in the NHL and only two have vacancies; the Capitals and — you guessed it, Brooklyn’s favorite major league hockey team.

Logic dictates that — unless the 55-year-old feels like retiring, working in the Kontinental Hockey League or seeking Unemployment Insurance — there’s a chap named Lou Lamoriello who needs an experienced, Cup-winning mentor.

Yoo-hoo, moo-hoo, wasn’t it Larrupin’ Lou who said “I’m looking for the best coach available” on June 6. What’s better than a Cup-winner?

Islanders President of Hockey Operations Lou Lamoriello explains his reasoning behind the reassignment of general manager Garth Snow and head coach Doug Weight in a conference call with the media.

The silence you now are experiencing must certainly be because of the possibility of negotiations speeding to be completed before the NHL Entry Draft begins on Friday in Dallas. Otherwise known as the calm before the storm.

Circling back to the present, The Maven must explain why the Winnipeg-born Trotz would leave a hotsy-totsy gig and adoring fans in the District of Columbia and points such as Virginia and Maryland. Here are some reasons:

DOUGH RE ME:

Had Trotz remained in Washington — based on contract small-print, etc. — he wouldn’t make as much money as he would elsewhere; and that includes Brooklyn-Uniondale.

NOTHING MORE TO ACCOMPLISH:

One Cup in America’s Capital is enough in 44 years. Trotz is the kind of guy who loves a challenge and this one has been accomplished. Why not help re-build the Isles with Larrupin’ Lou? Yeah, why not?

NOT TOO CRAZY ABOUT HIS EX-BOSS:

Trotz and his former boss Brian MacLellan were off the same page as much as on or, as the song goes, “I Got It Bad And That Ain’t Good.”

Translated, Barry has had his fill of Brian and now, there will be a brief pause for “Station Identification” to determine whether Trotz next station is Atlantic Avenue on the Brooklyn subway line.

But, then again, there just may be some hidden reason why Trotz wants a sabbatical.

Even if Barry does take a coaching break, there still is another Cup-winner available who’s a bit younger than Trotz.

Hey, the second best hockey bauble in North America is the American League’s Calder Cup. The Toronto Marlies’ Sheldon Keefe, just orchestrated a seven-game win over the Texas Stars and Shelly would love to graduate to the NHL.

Two Cup-winners, one of them could be in Brooklyn faster than you can say Take The Q Train!

P.S., when we’re talking about Lou Lamoriello, we have to be prepared for a surprise, and who knows which way Lou will go.