HOUSTON — With positive vibrations oozing out of every pore in the Yankees’ clubhouse, Masahiro Tanaka put up a wall to keep the slightest drop of negativity out of his head.

Anointed Thursday by Joe Girardi as the Yankees’ ALCS Game 1 starter against the Astros on Friday night at Minute Maid Park, Tanaka was asked about the beating he absorbed from the Astros in the middle of May.

“Just going into the big game [Friday] you don’t want to sort of have that negative feeling. So, to be honest with you it’s not something I really want to get into,’’ Tanaka said. “But what I can say is that I feel I am a different pitcher from that particular game earlier in the season.’’

The Yankees sure hope so because on May 14 at Yankee Stadium, the Astros ripped into Tanaka for eight runs and seven hits in 1 ²/₃ innings on the way to a 10-7 win.

It was the only time Tanaka faced the highest-scoring lineup in the majors.

Coming off a scintillating ALDS in which the Yankees got out of a 0-2 hole in the best-of-five series, they feel confident Tanaka will be more like the pitcher who held the Indians scoreless in seven innings of a 1-0 win in Game 3 that started the dramatic comeback.

For Tanaka, his fourth season with the Yankees was a different one. He posted a pedestrian 13-12 record and a 4.74 ERA in 30 starts. Yet, the right-hander, who can opt out of a contract that has three years and $67 million remaining on it, said the adversity helped him prepare for this.

“I just think being able grind through that up-and-down season that I had. I think because of having that I feel like I was able to pitch the way I pitched,’’ said Tanaka, who preceded the Game 3 gem by striking out 15 Blue Jays in seven innings Sept. 29.

While AL MVP candidate and AL batting champion Jose Altuve and the Astros’ lineup that led the majors with 896 runs will present challenges for Tanaka from top to bottom, the Yankees will face nemesis Dallas Keuchel.

Keuchel has dominated the Yankees in the regular season as well as the AL wild-card game in 2015 at Yankee Stadium. Justin Verlander, meanwhile, arrived in a trade from the Tigers to solidify the rotation.

Keuchel faced the Yankees once this season and delivered six shutout innings in a 3-2 win on May 11. In six regular-season starts against them, Keuchel is 4-2 with a 1.41 ERA.

“I think it’s just been a culmination of command, location, maybe a little bit more confidence,” Keuchel said. “And just because it’s the Yankees you kind of get a little bit more amped and a little more jittery because it is the pinstripes and such a storied organization.”

The Yankees could use Aaron Judge to reintroduce himself to the postseason. After homering in the wild-card game against the Twins, Judge is 1-for-20 (.050) and has struck out 16 times.

Though many believed a Indians-Astros ALCS would determine who went to the World Series, Astros manager A.J. Hinch said he isn’t shocked to see the Yankees.

“I’m not very surprised. You just never know in the playoffs. These short — I say short series, it’s only five games — but it shows to you there’s a lot of resolve on the other side for them to be down 2-0, especially with the stress that came with it and how they got there, these guys have been fighting,’’ Hinch said, referencing Girardi’s botched handling of the challenge procedure that led to the Yankees losing Game 2.

“The wild-card team that wins, that goes on and then gets down 2-0 and then all of a sudden fights their way back against one of the best teams in baseball and ends up in the American League Championship Series, there’s something right going on over there. So I’m not surprised.’’