Domingo German pitched well Saturday both before and after suspicion struck about what was on his pitching hand and how much it was aiding him in dominating the Twins.

It is worthwhile to use before and after as a defense of German. But it also plays into a bigger-picture issue for the Yankees — they need him to be good, not just on this day of controversy, but afterward as well.

That’s because, as manager Aaron Boone made clear before the Yankees’ 6-1 victory, while Carlos Rodon and Luis Severino are progressing well from their ailments, they are weeks away from a return. And aside from two precocious, surprising efforts from Jhony Brito, the Yankees had offered two distinct rotations this year: a latter day Spahn and Sain with Gerrit Cole and Nestor Cortes, and then a pray-for-rain wasteland.

Cole and Cortes had combined for a 1.96 ERA in six starts compared to 7.14 by Brito, German and Clarke Schmidt in their eight games. That is why Clay Holmes blowing the game Friday night after a stellar effort by Cortes hurt the Yankees so much. In this period of rotation renovation, Cole and Cortes have to represent victories for the Yankees.

But following a Brito debacle Thursday and a 4-3 setback Friday, the Twins had two straight wins at Yankee Stadium after having gone 3-24 in their previous 27 games (including the playoffs) in The Bronx.

So the Yankees needed German to offer length and quality Saturday. And he was coming off a career-high five walks against the Guardians, when he needed an uneconomical 87 pitches in lasting just three innings. He opened the game Saturday by going 3-1 to Edouard Julien before landing two changeups to strike out the leadoff hitter. He threw just one more ball during the first inning in striking out the side.

His changeup and curve were particularly overwhelming as he went nine up, nine down. As part of a random check following the top of the third, crew chief James Hoye said he found nothing sticky on the righty’s glove and glove hand, but felt a pitching hand that was “tacky.” He asked German if it was rosin and the starter said, “Yes.”

Hoye said the umpires have gone through training to differentiate various substances — from something like the illegal Spider Tack to the legal rosin. He felt this was rosin. Still, Hoye said, he told German to wash it off, which the umpire said is within his discretion. He said German could have refused because rosin is legal, but — Hoye said — that would have opened the door to more concerns about the substance. In hopes of elevating offense, MLB again is trying to crack down on the illegal sticky substances that allow pitches to create more deceptive spin.

German said he keeps rosin in the dugout and grabbed some on the way out for the fourth. As part of new rules this year, the umps can do inspections at any time to search for illegal substances. Hoye said there was still some tack on German’s right pinky. He consulted second-base ump D.J. Reyburn and two determined because it was not “a foreign substance,” and because they did not think it was having a material impact on German’s pitches, that this did not rise to an ejectable offense.

Twins manager Rocco Baldelli did not imply it was an illegal substance, but he was furious that German was given a directive, did not comply fully and was allowed to stay in the game. Baldelli was ejected for arguing.

German was not rattled by the controversy or delay. He struck out two more in both the fourth and fifth en route to 11 in his 6 ¹/₃  innings. He did not lose a perfect game until Christian Vazquez and Michael A. Taylor singled consecutively with one out in sixth. But he got Julien to ground to first and got Yankees killer Carlos Correa to fly to right.

The velocity average on each of German’s different pitch types remained consistent through  the third inning and afterward. The most discernible difference was an average drop of 107 revolutions per minute on his curveball from before to after, but there were still curves after the fourth inning that he had at the top of his spin rate.

Backed by a terrific all-around game from Anthony Volpe, homers by Kyle Higashioka and Anthony Rizzo and a key two-run double by Giancarlo Stanton to provide breathing room after Minnesota closed to within 4-1 in the seventh, the Yankees avoided — at least for one day — losing their first home series to the Twins since 2014. Cole will start Sunday as the Yankees try to earn a split.

But Cole and Cortes cannot start all the games between now and whenever Rodon and Severino are active. The Yankees are going to need others, like German, to pitch well.

Or else they will be in a particularly sticky situation.