Major League Baseball has become a playoff sport just like the National Hockey League, just like the National Basketball Association. Pennant races are obsolete. Regular-season powerhouses that habitually fall short in the postseason are increasingly perceived as little more than imposters.

And here I am at Yankee Stadium, where the Pinstriped home team clinched its second American League East Division title in three years with a 10-1 victory over the Orioles, behind a dominant performance on the mound from Gerrit Cole and a dominant performance at the plate by Giancarlo Stanton.

What?

After 15 years, did I say something?

The Yankees deserve a mountain of credit for this after overcoming multiple challenges throughout the season that started with Cole on the IL. The rotation carried the day early. The bullpen underwent several changes but has stabilized this important time of the year. Judge is having one of the best seasons in modern history. This has been a resilient, mentally tough unit. Finishing first should always be appreciated.

But if the Yankees do not follow this division title with their first World Series championship since 2009, the regular season success will recede quickly. Finishing in first place without a championship will mean as much as finishing in first place did to the hockey Rangers when they failed to win the Cup.

The burden of proof is on the Yankees.

The burden of proof also rests on the folks who will construct the postseason roster. Before the clincher, Aaron Boone faced a bevy of questions about the situation in left field, where the Yankees manager and hierarchy have a good-field, no-hit option in Alex Verdugo and a good-hit, unreliable-field option in Jasson Dominguez from which to choose.

Boone spent a few minutes analyzing the situation before this final game of the series against Baltimore, the first of two in which the Yankees were undermined by baserunning blunders by Juan Soto and Gleyber Torres on Tuesday and then by Dominguez’s misadventure Wednesday.

And the fact of the matter is that baserunning and defense become more important in autumn than the summer. Fundamentally, details matter. Fundamentally, the Yankees haven’t always been best-in-class in that category.

Perhaps coincidentally, but probably not, the Yankees have lost four of seven postseason rounds — not including a pair of one-game, wild-card knockouts they split — since Boone took over in 2018. Situational acuity is paramount in the playoffs.

I understand Dominguez’s promise. I get the electricity he can bring to the plate. He is a threat. It is all in front of him. But at the same time, catchable fly balls have been landing behind him in left field, a position the 21-year-old is attempting to learn after spending most of his life playing center field. The affable young man is a threat out there, too.

And I surely recognize Verdugo’s season-long issues at the plate. When at the bottom of the order, the 28-year-old, six-year MLB veteran essentially shortens it. His numbers at the plate have been inferior all season. He can devolve into an offensive black hole.

But Verdugo can catch the ball. And just about all the time.

The Yankees need people to catch the ball in the playoffs. Just about all the time.

And that is why Verdugo should get the starting assignment for Game 1.

For as Boone said, “Especially in the postseason, outs need to be outs.”

And as Boone added: “[Defense] is a big factor.”

Long-term, Dominguez has the athletic ability to become an outstanding left fielder if Judge continues his career in center. No one doubts that.

But by next week?

Players should not be learning new positions in the playoffs.

This, too: Dominguez was slashing .200/.294/.356 with a .650 OPS two homers and four RBI in 45 at-bats entering a Thursday game in which he went 0-for-2 with a pair of Ks, a walk, a stolen base and a run scored before Verdugo replaced him in the seventh inning with a 7-0 lead — and smacked a home run in the eighth.

In other words, this is not Shane Spencer in 1998, when the-then 26-year-old slashed .373/.411/.910 with a 1.321 OPS with 10 home runs and 27 RBIs in 67 September at-bats to force his way into the postseason starting lineup six games for perhaps the greatest baseball team of all time.

The Yankees do have the theoretical option of moving Soto from right field to left, where he started his career as a 19-year-old in Washington, so that Judge could shift to right and thus leave center field open for Dominguez. You may have noticed this year that catching fly balls has been a challenge at times for Soto, too.

But of course, that’s what the Yankees need, all right, a postseason fire drill in the outfield.

There is no need to complicate this. The postseason Yankees will need to master details more adeptly and consistently than the regular season division champions. The playoffs are different. The Yankees will need to catch the ball.

The Yankees will need Verdugo in left field.