BOSTON — You know these are strange days at Fenway Park when a visit from the New York Yankees feels like the undercard before back-to-back series with the world champion Chicago Cubs (how strange does that still sound?) and the suddenly loathsome Baltimore Orioles.

Against that backdrop, then, maybe this word of warning won’t seem so weird to the Boston Red Sox and their fans: Don’t sleep on the Yankees.

It was clear even through the fog that settled over the Fens on Wednesday night. The Baby Bombers are probably still a year away from being serious pennant contenders again, but like objects in the Red Sox’s rearview mirror, they are closer than they appear.

Mookie Betts, Xander Bogaerts and the rest of the Red Sox’s kiddie corps was supposed to dominate this year’s installment of The Rivalry, and odds are, they still will. But the Yankees won the first meeting of the season 3-1 before the smallest crowd for a Sox-Yanks game at Fenway since 1997 (32,072), and two of their brightest prospects led the way.

Hard-throwing right-hander Luis Severino delivered seven scoreless innings, and hulking slugger Aaron Judge smashed an opposite-field two-run home run through mist and a 50-degree chill against reigning Cy Young winner Rick Porcello. Judge, who is 6-foot-7 and 282 pounds, also snared Bogaerts’ foul ball by diving headlong over the short wall in right field, a downright terrifying sight for the patrons in the first row.

“I don’t think you would want to be in that position,” Bogaerts said. “He’s a pretty big guy. I looked at him when he was at second base. He looked as big as on TV. He’s a big boy.”

Judge has hit seven home runs in 64 at-bats, four fewer than the Red Sox’s team total through 20 games. The learning curve was supposed to be steeper than that, and as the league adjusts to Judge, things figure to get tougher. It’s still early, after all, and far too early to get caught up in the Yankees’ majors-leading plus-32 run differential and declare them the second coming of New York’s 1996 dynasty starters.

But the Yankees can still get better, too. They are playing without injured catcher Gary Sanchez and shortstop Didi Gregorius. Promising rookie first baseman Greg Bird is 6-for-51 with one home run, and ace Masahiro Tanaka has completed seven innings only once in four starts.

Ultimately, the Yankees are probably closer to where the Red Sox were two years ago. It took several times through the league for Bogaerts, Jackie Bradley Jr. and even Betts to emerge as All-Stars. But they led the Sox to a 32-26 record over the final two months of the 2015 season, a precursor to 93 wins and a division title last year.

The Red Sox weren’t a team anybody wanted to play down the stretch in 2015. The Yankees’ holdovers from two years ago can vouch for that. The Sox took three out of four games in the Bronx during the final week of the season and delayed the Yankees’ wild-card-clinching party.

And these Yankees figure to be no more of a pushover in the Red Sox’s march toward another American League East crown. That’s easier to see than the long foul ball hit by Josh Rutledge in the ninth inning that, had Sox manager John Farrell not “lost it in the fog,” would’ve looked for a moment like it might win the game against Yankees closer Aroldis Chapman.

“They’re executing in every phase of the game,” Farrell said. “They are probably a little bit more aggressive on the basepaths this year with the personnel that they do have. Their pitching has been very steady, strong for that matter, particularly when you get to the bullpen. They come in playing with a lot of confidence. They are scoring well and they aren’t giving up many either. They are playing well.”

Well enough, certainly, to merit your attention.