The NL strikeout leader was at Citi Field last night and his name was not Matt Harvey.

A.J. Burnett — 16-10 with a 3.51 ERA last year with Pittsburgh — is 3-3 with a 2.57 ERA and 62 strikeouts this season, when the Yankees are paying $8.5 million of his $16 million salary.

The consensus is that he is beneficiary of a change of scenery, mainly in leaving the stress of the Yankees and the AL East. One NL personnel man echoed the theme of three executives asked about Burnett by saying the righty “is better and the reason isn’t stuff — it’s environment. Burnett is a classic small-market guy; the less the games matter the better he pitches. It’s not unlike Kenny Rogers or others who have struggled when they went to bigger markets to play where every game mattered. It’s easy to pitch in Pittsburgh because all you have to do is finish .500 whereas with the Yankees it’s a relentless pursuit of the next World Series title.”

Pirates manager Clint Hurdle actually said big responsibility is central to Burnett’s Pirates success, explaining, “he was just another guy in New York. He is not another guy in our clubhouse. He is our guy. ... He has met the challenge and been up to it. He has been absolutely awesome.”

Russell Martin, who has caught Burnett in both locales, said, “being The Guy has helped him. He is just being free out there, just being himself. He is not adding pressure on himself.”