Chris Sale of the Red Sox stands on the mound...

Chris Sale of the Red Sox stands on the mound after surrendering a home run against Chase Headley of the Yankees at Yankee Stadium on Sunday, Sept. 3, 2017. Credit: Jim McIsaac

Boston ace Chris Sale may be the very best pitcher in the American League. He certainly is one of the two front-runners — along with Cleveland’s Corey Kluber — in the Cy Young Award conversation.

Sale, however, has had one very big issue this season: He can’t beat the Yankees.

They got him again on Sunday night in a 9-2 rout of the Red Sox at the Stadium, a win that shaved AL East-leading Boston’s lead to 3 1⁄2 games. When Sale left a 3-0 game in the fifth, he had allowed three solo homers in 4 1⁄3 innings — and to get 13 outs, he needed 109 pitches.

“We had a great approach. We know we’re facing a really good pitcher who has been tough on us,” manager Joe Girardi said. “We haven’t scored a lot of runs . . . but our guys were big tonight: home runs, long counts and just really good at-bats.”

Sale’s record is 15-7 and his ERA is 2.85. With 270 strikeouts in 189 2⁄3 innings pitched, he has a chance to be only the second pitcher since 2002 to strike out 300 in a season (the Dodgers’ Clayton Kershaw had 301 in 2015) and the first American League pitcher to accomplish the feat since Pedro Martinez did it for Boston in 1999.

But the southpaw has gone up against the Yankees five times this season and doesn’t have a win to show for it. And it isn’t as though he hasn’t been the same stellar pitcher he’s been all season, because he’s been great against them.

In the five outings, he has a 2.65 ERA and 1.02 WHIP with 50 strikeouts in 34 innings.

And his record in those games is 0-3.

The common themes in holding Sale winless have been patient, grinding at-bats by the lineup and matching him with a strong starting pitching performance. He’s been outdueled by three different Yankees pitchers — Luis Severino, CC Sabathia and Masahiro Tanaka. But the offensive approach has been the same.

In Sunday night’s game, the Yankees fouled off 26 pitches against Sale, including 15 in the fourth and fifth innings.

“They’ve got to adjust to me just like I’ve got to adjust to them,” Sale said. “That’s what the game is about: adjusting. They were putting long at-bats together, fouling some pitches off, taking some good pitches. It was up to me to make an in-game adjustment, and clearly I didn’t.”

“We had a lot of good at-bats where we laid off some tough pitches,” said Chase Headley, who homered off Sale in the third inning. “When a guy has really good stuff, you’re going to foul pitches off. We did a good job with laying off close pitches and got his pitch count up and got him out of the game.”

If it sounds reminiscent of something recent from the Yankees-Sox rivalry, it should. The Yankees had similar success with a similar approach against Martinez when he pitched for Boston.

Martinez started 27 regular-season games for the Sox against the Yankees and pitched 180 innings to a 3.30 ERA with 230 strikeouts. That’s impressive.

His record was 9-10.

Boston’s record in those games was 10-17.

The key is to run up Sale’s pitch count, get him out of the game and try to beat Boston’s bullpen, just like the approach had been against Martinez. On July 15, Sale allowed no runs and three hits with 13 strikeouts in 7 2⁄3 innings against the Yankees — and got a no-decision when Matt Holliday hit a tying homer off elite closer Craig Kimbrel in the ninth inning. The Yankees went on to win in 16 innings.

“We have a bunch of guys that grind out at-bats, and that’s what it takes with a guy like Sale,” said Holliday, who combined with Todd Frazier to hit back-to-back homers off Sale in the fourth. “You have to go and compete and grind, just know he’s going to get you some and hope he makes mistakes.”

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