OAKLAND, Calif. — Hearing Aaron Judge getting loudly booed every time he approached the plate Tuesday night about 85 miles from his hometown wasn’t the only thing different about the first of three games against the A’s.

For the first time this season, a season interrupted for two months by a strained left oblique muscle, Judge homered to left field in a 6-2 loss at the dilapidated Oakland Coliseum.

Throughout a 21-game slump that started July 25 and has shown signs of vanishing in Judge’s past three games entering Wednesday night’s, he emphasized the Yankees winning (they were 14-7) during his struggles at the plate. In those 21 games (20 starts), Judge hit .148 (12-for-81) with a homer, four RBIs, a .501 OPS and fanned 31 times.

That outlook didn’t change Tuesday night after smoking his 13th home run to the seats above the left-field scoreboard off Joakim Soria starting the eighth, a blast measured at 467 feet and clocked at 116 mph off the bat.

Asked about hitting a homer to left for the first time this year, Judge said as long as the ball disappears over a fence, it is OK.

“Direction doesn’t matter, left, right, center,’’ said Judge, who was unaware of the booing and went 5-for-12 with two RBIs in his previous three games before Wednesday night. “I was glad to get one and hoping to start a rally but didn’t do it.’’

Not much got started for the Yankees against A’s starter Homer Bailey, who gave up Gary Sanchez’s first-inning homer and nothing after that. In 5 ²/₃ innings the veteran right-hander allowed seven hits, didn’t issue a walk and fanned eight. It was the second time Bailey beat the Yankees this year, after winning April 18 in The Bronx while with the Royals.

The combination of Judge’s power and Yankee Stadium’s cozy right-field dimensions produce many homers to right, and when Judge is going good there isn’t any part of any park able to hold him.

Nevertheless, for a hitter who swatted 11 of 27 homers last season to left and left-center, 23 of 52 in 2017 and two of four in 2016, not having hit one out to left or left-center through 69 games was odd.

Judge and the Yankees haven’t used the lingering effects to his oblique strain as the reason for the recent slump.

“I have felt good [at the plate] for a couple of months now,’’ Judge said. “Hits will start falling.’’

A hot Judge across the final 36 games (including Wednesday’s tilt) would certainly help the Yankees cop home-field advantage for as long as they are alive in October. They held a two-game advantage over the AL West-leading Astros for home field during the AL playoffs and were tied with the Dodgers for the best record (83-44) in baseball going into Wednesday’s schedule.

The Yankees believe they will get Luke Voit, Edwin Encarnacion and Giancarlo Stanton back from the injured list where Aaron Hicks also resides. However, what Voit, Encarnacion and Stanton look like at the plate when/if they return isn’t known.

Just as they have done without Miguel Andujar (12 games) and Stanton (nine), the Yankees have thrived with Voit and Encarnacion on the IL.

DJ LeMahieu will get AL MVP votes and he led the AL in hitting with a .338 average entering Wednesday night’s game against right-hander Mike Fiers. Gleyber Torres has laughed in the face of the sophomore jinx by hitting .281 with a team-leading 29 homers and 73 RBIs, second to LeMahieu’s 86. Gio Urshela was hitting .338 and on the verge of qualifying for the batting race. A player needs to average 3.1 plate appearances for every game played by his team to qualify and Urshela was averaging 3.0.

Yet, with the Yankees looking to close out the second-place Rays (10 lengths back) in the AL East, they would certainly welcome Judge’s home-run prowess back into the top of the lineup.

No matter what field those homers are hit to.