There were no fans allowed inside Citizens Bank Park on Thursday night, but the Phillies seemed to find a way to gain a home-field advantage against the Yankees thanks to a group of fans and an air horn.

Yankees manager Aaron Boone complained to the umpires between innings of the Phillies’ 5-4 win about the noise coming from just outside the ballpark. The Phandemic Krew — a group of diehards who have stood on 10th Street outside the gates to Ashburn Alley during games — was blaring an air horn just as the Yankees were throwing their pitches.

“The environment we’re in, it’s almost like a golf environment where that sudden thing can [cause a distraction]. So I thought there was a timing element to it,” Boone said. “I didn’t necessarily think [the umpires] would be able to do anything about it. I didn’t necessarily know who or where it was coming from, but it was something I at least wanted to point out.”

The umpires told Boone that there was nothing they could do because the fans were not inside the ballpark. The group of fans caught wind of Boone’s complaints — they follow the game on 10th Street through radio and TV — and started chanting his name.

The fans seemed to stop blaring the horn during pitches but did use it to celebrate big moments for the Phillies. A night earlier, the Phandemic Krew hired a drumline to play during the game.

“The drumline yesterday was crazy,” Yankees starter Jordan Montgomery said Thursday. “I heard them, but they were no different than fans in the stands. I heard yesterday that their announcers were being really loud mid-pitch during J.A. Happ and the other guys’ pitches, and not doing the same for their team. It’s kind of messed up that they’re out there, but it is what it is.”

Phillies TV broadcaster Tom McCarthy tweeted Thursday night “that’s funny” in response to Montgomery’s claims that the announcers were distracting the pitchers. The ballpark is eerily quiet without fans, but it’s unlikely that McCarthy and his partners could provide a distraction. And it’s even more unlikely that they would intend to provide one.

But the fans? That distraction was real.

“You could hear it. It was pretty loud,” Yankees outfielder Mike Tauchman said Thursday. “Philadelphia is known for having a pretty passionate fan base and those guys want to find a way to support their team even though they can’t be in the stadium, and that’s how they chose to show their fandom tonight.”

Phillies manager Joe Girardi said he was unsure what Boone was asking the umpires about. Girardi said Philadelphia has great fans who are extremely passionate and “offer a great home-field advantage.” And now they managed to provide a home-field advantage during a pandemic when the gates are locked and the paid attendance is zero.

“It’s nice to hear something even if they are quite far away. They had the horn going pretty well tonight and I heard a few of their chants,” Phillies catcher J.T. Realmuto said. “It’s fun to get a little bit of fans out there. It’s better than listening to silence.

“It definitely doesn’t hurt. It’s nice to hear something out there and hear that support. It’s better to have them out there than not.”