Aroldis Chapman of the Yankees reacts in the seventh inning against...

Aroldis Chapman of the Yankees reacts in the seventh inning against the Mets during the first game of a doubleheader at Yankee Stadium on Sunday. Credit: Jim McIsaac

SEATTLE – Gerrit Cole isn’t the only high-profile Yankees pitcher who has struggled since word came down in early June Major League Baseball intended to crack down on the use sticky substances on baseballs.

Aroldis Chapman brought a 22.24 ERA over his previous nine outings into Tuesday night’s series-opener against the Mariners, a stretch that included a blown save in the first game of Sunday’s doubleheader split against the Mets at the Stadium.

The blown save, his third in the nine games, caused Chapman to be lustily booed off the mound as he departed the field Sunday. On Monday night, the frustrated closer — whom Aaron Boone indicated over the weekend could be in danger of momentarily losing that job — fired back.

Not specifically against fans who have booed him, but his critics in general.

"For all those people that criticize my bad moments, I will tell them that I do not know how my story ends, but in its pages you will never read, ‘I gave up,’" Chapman posted, in English and Spanish, on Instagram. "So I will move on. I still have many wars to win and many mouths to shut up."

Sunday, when Chapman allowed Pete Alonso’s game-tying homer in the seventh and ended up allowing three runs without recording an out, was latest implosion in a stretch of games that has seen Chapman’s ERA climb from the 0.39 it was before action on June 10 to 4.71.

The starting point was June 10 in Minneapolis, when Chapman allowed a pair of two-run homers in a stunning 7-5 loss to the Twins, an outing in which the lefthander failed to retire a batter.

Chapman’s velocity was noticeably down that night, but it returned in ensuring outings, eliminating injury as a potential issue.

What hasn’t been eliminated as a contributing factor to Chapman’s troubles, which had him, as of Tuesday night, with a tenuous hold at best hold on the closer job, is the MLB crackdown on illegal substances.

Though Chapman has said, and continues to say, he has never dabbled in the use of those substances and his manager, Aaron Boone, has singled out mechanics as being the primary issue, the numbers are what the numbers are since the crackdown.

And until Chapman, who has struck out just six and allowed four homers during this nine-game skid, works through his difficulties, Boone is in the difficult spot of not entirely trusting his closer.

And, indeed, Boone on Sunday didn’t outright dismiss the possibility of Chapman, for the moment, being demoted from closer, mentioning Jonathan Loaisiga and Chad Green, who pitched the final three innings of the Yankees’ 4-2 victory in Sunday’s nightcap, as potential options.

"I’ll consider a number of things," Boone said. "Those are the conversations that we have. But we may not have that option Tuesday. Green and Lo could be down. So we’ll have those conversations and try and do what’s best for the team and for those individuals."

Asked before Tuesday night’s game who his closer would be, should one be needed, Boone said, "it could be anyone," Chapman included.

The 33-year-old Chapman, who found out early in the day Sunday he had been named an All-Star for the seventh time in his career, has been down this road before, the case with just about any closer who has done the job for an extended number of years. Back in August 20017, for example, then-Yankees manager Joe Girardi removed Chapman from the closer role to get the slumping reliever back on track.

The move worked and, some three weeks later, Chapman again had Girardi’s full trust.

Chapman, as of Tuesday, had not yet been stripped of the job but, as Boone is making clear, he has anything but a lock on it.

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