Aaron Boone has backed Gary Sanchez since he was hired as manager nearly two years ago.

And that hasn’t changed even as the catcher’s prolonged slump has extended well into October.

Since his return from a strained groin, Sanchez closed out the regular season 1-for-6 with four strikeouts and is just 2-for-21 with three walks and 10 strikeouts in six playoff games. He’s yet to drive in a run during the postseason and in his last two games against the Astros in the ALCS, he’s hitless in nine at-bats with five strikeouts.

Only the Cardinals’ Dexter Fowler has been less productive in as many games as Sanchez this postseason.

And he couldn’t stop a Zack Britton wild pitch from getting by him with the bases loaded, leading to a run in the top of the seventh of his team’s Game 3 loss Tuesday.

In the midst of all that, Boone once again defended his catcher and showed no inclination to make a change to Austin Romine behind the plate.

“Let’s start with the [defensive] side of the ball, which completely gets lost in this,’’ the manager said during a conference call after Wednesday’s Game 4 was postponed due to rain. “And without sugarcoating it at all, he’s been excellent behind the plate from a game-calling standpoint, from a game-plan, target, receiving. A lot of people are making a lot of the block. There’s a lot of 94-mph fastballs that guys don’t block. Guys aren’t always set up to block a fastball. That’s kind of a 50/50 play. … The bottom line is his body of work in this postseason, and frankly down the stretch in the second half of the season defensively, has been excellent.’’

Even if his work behind the plate and with the pitching staff has pleased Boone, the Yankees can’t expect to beat Houston without more production from Sanchez, who at times is the team’s most fearsome hitter.

“I always feel like he’s a pitch away or an at-bat away from really getting locked in and changing the course of a game,’’ Boone said. “So clearly he hasn’t been at his best offensively, but with a guy as talented as he is, I think that’s right around the corner, always.’’

It’s also not the first time Sanchez has struggled against the Astros this time of year. In the 2017 ALCS, Sanchez went 5-for-26 with two extra-base hits, one walk and nine strikeouts as the Yankees lost in seven games.

He hit well in six games versus Houston during the regular season (8-for-22 with two doubles and a pair of homers). Some of that production came while facing pitchers who are not factors in this series — but not all of it.

Asked what’s been different about their approach against Sanchez during the playoffs, Houston manager A.J. Hinch declined to get into details.

“I don’t want to give my opinion on anything we’re doing until we see what’s next,’’ Hinch said Wednesday. “Obviously, we’re trying to attack guys where we think we can get them out. We’re trying to avoid the big swing and big moments, with Sanchez in particular. We’ve done a pretty good job of making pitches from a strategic standpoint, [but] we’ve got too much baseball left to play for me to evaluate his performance.’’

Boone didn’t want to blame the time off Sanchez had later in the year.

“Hitting is hard,’’ Boone said. “Sometimes you kind of lock it right back in right away. Other times it takes a little while to find that consistency. … But I feel like Gary has been back long enough now to certainly be in the flow and the rhythm of regular play. Again, hopefully this starts real soon for him.’’