It was a beautiful afternoon, bright sunshine and blue skies, a perfect setting for baseball, maybe the perfect milieu for the Yankees to bid adieu to an old friend named Vin Scully. These are the kinds of days perfectly designed for the baseball romantics and their paeans, poems and purple prose.

Grab a hot dog. Sip a cold beer. Slather yourself in sunscreen …

Well, it was a good plan, anyway.

Seven batters into the game, the Mariners had six runs and the 42,169 who’d opted for a businessman’s holiday at Yankee Stadium were already plenty ornery. And with cause. That was the artist formerly known as Gerrit Cole getting lit up. And Luis Castillo, the center of so many Yankees-fan fantasies these past few weeks, was lined up, six runs to the good.

It ended 7-3. Bad day all around.

“It’s hard to believe how it blows up so quick,” Cole said later.

Cole was probably one batter from an early shower, but did recover to eat six innings and keep the Mariners off the board the rest of the way. “You try to be excellent. But the game tells us when we’re not.”

Later, he added a curious turn of phrase that someone ought to immediately slap on a T-shirt: “We’ve gotten baseballed.”

You can take that in any context you’d like. Cole, for instance, still spends most of his days as a commanding pitcher with superlative stuff. He has also had five different starts this year in which he has surrendered at least five runs, including the last two. That’s getting baseballed.

He tried to honor his between-starts strategy of trusting his instincts, yet those instincts urged him to eschew his 99-mph gas and throw first-inning sliders to both Eugenio Suarez and Jarred Kelenic; Suarez and Kelenic made both disappear. That’s getting baseballed.

Let’s go with the loose translation that getting baseballed means the game eventually finds you, no matter how well you’re playing. That can apply to an individual. And it can apply to a team. The Yankees — 12-15 over their last 27 games — have been getting baseballed at a lot higher clip than they were used to across the season’s first 3 ½ months.

And what’s notable — that’s the kindest way to describe it — is how the aspect of the Yankees that was cruising along at an almost historic pace, their starting rotation, is suddenly getting nicked and sliced and cut up. It’s not anything resembling DEFCON 2, not quite yet.

But what was once a reliable everyday strength has become something else. Cole’s ERA took a huge hit Wednesday, jumping from 3.30 to 3.56. Jameson Taillon’s is 6.25 in his last eight starts after he was pasted Tuesday. Luis Severino is on the 60-day injured list and his replacement, Domingo German, is pitching to a 6.39 ERA. Nestor Cortes is still a feel-good gem of a story, but he’s looking at an innings drag at some point.

And Jordan Montgomery is a Cardinal.

Of the flurry of trade-deadline maneuvers Brian Cashman pulled off, that was a genuine head-scratcher. Harrison Bader, acquired for Montgomery, is a Bronxville kid with a dynamic glove, but he’s hurt right now and has a career OPS+ of 99. Plus, the Yankees, when healthy, have more than enough outfielders.

Maybe the Yankees had already determined that Montgomery wasn’t going to be part of their postseason rotation, but he is a durable innings-eater at a time when that would be an especially useful asset. Cashman did bring in Frankie Montas, with the expectation that his 4-9 recoord is a product of pitching for a dreadful Athletics team. He also has to hope that Montas’ jarring home-road splits — he pitched to a 2.36 ERA in Oakland’s spacious RingCentral Coliseum, and 5.01 everywhere else — are a mere statistical anomaly.

(You know who had similar splits when he was imported from Oakland to New York in 2017? Sonny Gray. Hey, I’m just the messenger.)

Look, the likelihood of the Yankees’ starters being as dominant in August as they were in June was always remote. The game doesn’t allow it. And nobody seems especially worried about Cole, which is good, because much of what the Yankees hope to accomplish in October is contingent on him being a legit ace. Which he was for five innings Wednesday. But he pitched six.

“There’s some wonky weirdness attached to that,” Yankees manager Aaron Boone said.

Is it really weirder than trading away a reliable, proven starter for no apparent reason? Yankees fans may have to ask themselves at some point if they aren’t the ones being baseballed.