Hmmmmm…Michael Pineda’s hand had something on it, all right. (Kathy Willens / AP)

The New York Yankees and Boston Red Sox are playing their first series of the season and — who knew? — there’s already a controversy.

Just what was that stuff on the hand of pitcher Michael Pineda? Was it dirt? Pine tar (shades of George Brett)? Oily gunk? Gunky oil?

Pineda, who gave up four hits and struck out seven in six innings in the Yankees’ 4-1 win in New York, had a simple explanation. “I don’t use pine tar,” he said. “It’s dirt. I’m sweating on my hand too much in between innings.”

Oh. The dirt hit the fan on social media, which exploded in conversation about just what the substance was during the game. The buzz reached Red Sox Manager John Farrell in the fourth inning and, sure enough, Pineda’s hand was fresh as a newly diapered baby’s bottom when he came to the mound for the fifth inning. So Farrell did not mention it to the umpiring crew.

“No one said a word,” umpiring crew chief Brian O’Nora said. “The Red Sox didn’t bring it to our attention, so there’s nothing we can do about it.”

Besides, doctoring the ball is part of long-standing baseball tradition. The Red Sox merely shrugged, perhaps because Clay Buchholz, the losing pitcher, was accused of funny business involving rosin and sunscreen last year. In the World Series, Jon Lester seemed to have something on his glove in Game 1, but there wasn’t a peep from the St. Louis Cardinals.

“No, especially on cold, windy nights, it’s tough to get a grip on the baseball,” Buchholz said (via ESPN Boston). “I had that instance last year in Toronto, people said I had stuff all over my body you can use — rosin, water, the whole sunscreen stuff, whatever. I’d rather have a grip on the baseball and semi-know where it’s going [than] have no grip and get somebody hurt.

“As hard as [Pineda] was throwing early, ain’t no one want to get hit, especially around the head. I don’t think any organization would want to do anything about it. Scuffing the ball is one thing, if you’re actually creating more control over where you want to throw it, giving you any type of edge. But as long as I’ve been around, I haven’t seen sticky substance give anyone an edge. If it gives them an edge, that’s another thing.”

Baseball does, of course, have a rule about this, even if it’s rarely invoked. A pitcher may not “apply a foreign substance of any kind to the ball” and “have on his person, or in his possession, any foreign substance.” The penalty is ejection and immediate suspension. Weigh that against the karmic consequences of one manager turning in another’s pitcher (when he may well have someone on his staff doing the same thing) and you see why everyone whistles and looks the other way. Yankees Manager Joe Girardi said repeatedly that, gosh, he “never saw it.”

“There is really not much for me to speak on concerning that,” Girardi said. “All I know is he pitched extremely well and we are glad to have him back.”

“Filthy stuff,” indeed.