Heather McMahan urged fans at the first tee to shout "f*** you Rory!" together after players were introduced to the crowd before the start of the afternoon session of the second day at Bethpage Black on Saturday.
It was one of a number of unsavoury incidents on a fractious, fraught day of action overshadowed by crowd problems and set the tone for a lot of the treatment McIlroy subsequently received.
McMahan was not the main announcer at the event, but was supposed to be entertaining the crowd.
A statement from the PGA of America, the event organisers, read: "Heather McMahan has extended an apology to Rory Mcllroy and Ryder Cup Europe and has stepped down from hosting the first tee of the Ryder Cup."
European captain Luke Donald later accused American fans of "crossing the line" on Saturday after his players, most notably McIlroy, were subjected to heckling and abuse, with comments repeatedly aimed at the Northern Irishman as he prepared to play shots.
At one point in the morning, McIlroy shouted at a fan and his afternoon match was held up a number of times as appeals for calm - some from opponent Justin Thomas - were made.
Donald said: "It was loud, it was raucous.
"What I consider crossing the line is personal insults and making sounds when they are trying to hit on their backswings or very close to when they are trying to go into their routines. That did happen a little bit."
The PGA of America did not comment when asked by the PA news agency about reports of further disturbances, including fighting, in the crowd.
Much had been made of the hostile reception Europe were likely to be given by a boisterous, partisan New York crowd.
McIlroy and partner Shane Lowry heard much of the abuse sent Europe's way, repeatedly clashing with fans on their way to a win in their match with Thomas and Cameron Young.
McIlroy described it as a "really challenging day", while Lowry seemed to relish the atmosphere.
"It was intense. It was like something I've never experienced," he said. "But this is what I live for. This is it. This is, like, honestly, the reason I get up in the morning, for stuff like this."
McIlroy said: "People can be their own judge of whether they took it too far or not. I'm just proud of us for being able to win today with what we had to go through."
The clashes were not only with the crowd, though.
Bryson DeChambeau screamed in the face of Tommy Fleetwood after his partner Justin Rose had complained about DeChambeau's caddy Greg Bodine walking across the line of his putt, with players and caddies getting involved in the spat.
"I was ready to hit my putt," Rose said. "I didn't feel like that space was being honoured. I made my feelings known. Asked him to move.
"Maybe not as politely as I could have done, but in the scenario, it's coming down the stretch, we both have a lot on our minds and it's intense out there."
Ultimately, Europe shut out the noise to win both sessions convincingly on Saturday and open up a commanding 11.5-4-5 lead.
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