Aaron Judge had the day off. Gary Sanchez is disabled. Greg Bird’s bat is disabled.

There are days when the much-ballyhooed Baby Bombers will look for guidance from the last vestiges of the old guard, and this was one of them.

CC Sabathia, the 3-2 winner Saturday over the Cardinals, reached back to a proud Cy Young past and showed you can be 36 years old and on the back nine of a 225-win career and pitch as if you are forever young anyway.

He is the Pinstriped Muhammad Ali, no longer able to float like butterfly, sting like a bee, but eminently capable of a treacherous Rope-A-Dope that leaves batters flailing away and frustrated and flummoxed and ultimately defeated.

“Just figured out how to get guys out with the stuff that I have,” Sabathia told The Post, “and being confident in it.”

He stands as a towering example to the young lions who now inhabit The Bronx of how you can reinvent yourself, even after a battle with alcoholism, as a brainy pitcher so many years removed from a brawny flamethrower.

“Well, it’s always fun to throw 97,” Sabathia said, and smiled. That was five years and 5 mph ago. “I don’t really miss it, though. I enjoy what I’m doing now. I feel confident that I can get hitters out with what I have now.”

And this is what he has now: “The backdoor slider, the cutter, the changeup,” Sabathia said. “I’ve been throwing everything on both sides of the plate, and I think it’s helped me a lot.”

The November cleanout of his right knee has mentally liberated him.

“I just wasn’t able to finish on my leg and move forward toward the plate,” Sabathia said. “But now, being healthy, I’m able to not spin off, everything’s directed towards the plate.”

Sabathia’s transformation has made him a marvel to teammates young and older.

“When you get to know CC and see what kind of person he is and how infectious he is in the clubhouse, obviously you want to see him do well, but it’s neat to be able to see him kind of figure out a way to still pitch really, really well later in his career,” Chase Headley said.

“He’s a guy that, regardless of the kind of stuff that he had out there, he’s gonna give everything he has. He knows what he’s doing, he doesn’t get rattled. It’s fun to play behind him. It’s just awesome.”

Sabathia lost his shutout in the eighth inning on his 97th and final pitch, when Jedd Gyorko belted an opposite-field home run, and tipped his cap as he retreated to the dugout to a standing ovation.

“He was pretty complete when he was winning 20 games and throwing 97 with a real good changeup and a slider,” manager Joe Girardi said. “He’s more creative now is probably the best way to put it.”

Of course it meant plenty to Sabathia to wear No. 42 and honor the memory and legacy of Jackie Robinson on a day when Girardi needed for him to turn back the clock without the services of Dellin Betances and Aroldis Chapman.

“It was exciting to be out there on the mound. … It’s a big day for baseball, African-American players, and to be able to wear 42 and get a win felt good,” he said.

He was poetry in motion to catcher Kyle Higashioka.

“It was nice to kind of get on the same level mentally with him and kinda have it go really smoothly,” Higashioka said. “Not too many guys can cover the inside corner and the outside corner at the same time, unless they have to cheat one way or the other.”

Sabathia is the longest-tenured Yankees pitcher. Brett Gardner is the longest-tenured Yankee. So it was fitting it was Gardner who walked and scored on a Carlos Martinez wild pitch in the first inning.

It was Gardner who raced down a screaming Randal Grichuk drive perilously close to the Budweiser sign on the left-field wall.

“That was a huge play … just kind of saved me and was able to go into the next inning confident,” Sabathia said.

The Yankees have won six in a row, and a confident Sabathia can change the complexion of a season.

“He knows how to pitch,” Higashioka said.