Yankees shortstop Didi Gregorius hits a solo home run against...

Yankees shortstop Didi Gregorius hits a solo home run against the Cleveland Indians during the fourth inning at Yankee Stadium on Sunday, Aug. 7, 2016. Credit: Kathleen Malone-Van Dyke

The fuse was lit weeks ago amid the long, dreary buy-or-sell debate that consumed Gotham through early summer.

But when the time came at last, the Bronx Bombers blew themselves up spectacularly, a display of player personnel fireworks that left them transformed even more thoroughly and quickly than anticipated.

The grand finale, fittingly, came courtesy of Sunday morning’s A-bomb from A-Rod, in which the Yankees and their most marketable — or at least most recognizable — employee announced that Friday would be his final game in pinstripes.

Whether it turns out to be Alex Rodriguez’s final game for any major league remains to be seen. But as the capper to two weeks that turned decades of Yankees philosophy on its ear, it was dramatic, and appropriate.

Gone: Aroldis Chapman, Andrew Miller and Carlos Beltran. Gone at the end of the season: Mark Teixeira. Gone on Friday: Rodriguez. Here: the future.

“This is what the organization wants right now,” Rodriguez told Fox — his past and perhaps future employer — in an interview posted as Sunday’s news conference began. “Obviously, there’s a shift. There’s a youth movement.”

Ya think?

The remarkable thing is how supportive most fans are of it. Their team entered Sunday’s game with a .500 record, still theoretically in contention for World Series championship No. 28.

But it seems everyone is on board with the housecleaning. As they should be.

Consider what happened when Derek Jeter retired after 2014: Didi Gregorius replaced him at shortstop. Now he is the best player on the team. On Sunday, he hit a home run — on Didi Gregorius Bobblehead Day. He’s 26.

Manager Joe Girardi seemed to tear up as he answered a question about his emotions regarding recent events.

“It’s been a tough week,” he said. “It’s been a tough month, for a lot of different reasons . . . To lose guys like this, it’s hard. Alex has meant a ton to me. This has been a tough month.

“Obviously, it’s a hot topic every day and it’s not an easy topic to talk about. So it’s taken its toll.”

That is the way a manager should feel. It is up to ownership and the general manager to put such feelings aside, as Hal Steinbrenner and Brian Cashman have done.

Cashman seems already to have been in the sell camp by late last month, but a three-game sweep at the hands of the Rays — including a four-strikeout game for Rodriguez — from July 29 to 31 sealed the deal.

“I think it might have been a mover of the needle for ownership,” Cashman said.

So, here we are. Finally. “It put everybody on heightened alert to ‘what’s next, what’s next, what’s next?’ ” Cashman said of the buy versus sell discussion. “You [reporters] have been living it. We’ve been living it. I think it’s a new opportunity.”

Cashman flashed his 2009 World Series ring in tribute to Rod riguez’s contribution to that championship. That was seven years ago, though.

The GM has been around the team for 30 years now and recalled Ron Guidry retiring during the 1988 season as an early eye-opener.

“It’s the one thing about this game: It’s always changing,” he said. “So it’s hard to see the ones you build better relationships with come and go.”

Lately, “go” has been the operative word.

“Clearly, there is a transition going on right now,” Cashman said. “This roster has been getting younger the last few years. It’s by intent. It’s stated publicly. It’s something that’s necessary and I think it’s an exciting time because there is some young blood that’s coming in here and they have big dreams and big hopes.”

He called it an “exciting narrative.” We’ll see. At least it’s a new one.

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 5 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME