"No, man," he said later, explaining himself. "Two outs."
He promised to alter his signal to avoid trouble in the future.
"We don't want any controversial stories here," he said.
Morgan preferred to talk about the Brewers' big win, but his inning-long interaction with the fans provided an interesting sideshow. He played on the boos throughout the rest of the inning, motioning repeatedly to the center-field bleachers and pounding his chest.
As the Brewers prepared to bat in the eighth, veteran umpire Joe West approached the Brewers' dugout for a word with Morgan. Brewers manager Ron Roenicke had a conversation, too, and said he thought Morgan's exuberance may have gone too far.
"But that's Nyjer," Roenicke said. "He's an emotional player. He's a vocal player. Have fun with it, which I like. I like his energy, I like him to have fun. But don't rile up people. ...
"I mentioned something to Nyjer. Hey, this guy has been awesome for us. So we'll keep him happy."
Friday's incident was not the first time Morgan's interactions with fans have gained notice. Morgan, then with the Nationals, served an eight-game suspension and was find $15,000 in September after he used inappropriate language toward Marlins fans at Sun Life Stadium and engaged in a physical confrontation with Marlins right-hander Chris Volstad. Prior to that, Morgan was suspended seven games for allegedly hitting a fan with a ball at Citizens Bank Park. The league later lifted that suspension.
Giants players declined to comment about Morgan. Brewers starter Shaun Marcum saw the great catch, but was focused on the next hitter when the fans and Morgan traded barbs.
"I heard everybody, but I wasn't paying attention. Who knows what he's doing out there," Marcum said. "He ran down a couple balls today. He did a great job out there."
Marcum painted Morgan's exuberance as a positive.
"That's Nyjer. He's excited," Marcum said. "He brings an energy to the field every day, and we're glad to have him here."
Morgan said he still roots for the Giants when he's not playing against them.
"I'm still a fan of the game of baseball, even though I play," Morgan said. "It makes it a lot more fun playing against the Giants. I watched the clincher. It was 'buzzy' around here then. I was loving it."
Morgan's favorite Giants player growing up is a familiar name to Brewers fans -- Jeffrey Leonard, who played in San Francisco from 1981 through his '88 trade to Milwaukee for Ernest Riles.