Granderson turned toward the Angels fan and admonished him after the incident.
Security appeared to subsequently escort the fan from his seat. On the eighth-inning play, J.B. Shuck had flied out to Granderson, who was returning the ball to the infield when he was touched in the back by someone reaching from the stands.
"He touched me and then I turned around," Granderson said following New York's 5-4 loss in 11 innings. "He was like. 'No, I didn't mean to.' I was, 'Hey, just don't touch me.' And that was it.
"Say whatever you want to say. Boo, cheer, clap, cheer for your team, cheer for the other team. But just don't physically touch the players."
Granderson acknowledged that he was concerned by the incident.
"You never know what's going to go on," he said. "The thing that was asked to me by the [Angels] team security was, 'Are you OK? Did anything happen?' I was like, 'Yeah, everything's fine.' But just the fact that I got touched during the act of the game while things were going on is obviously something to always be concerned about."
Granderson said it was the first time he had been touched by a fan while on the field in his career.
"Hey, if the ball is coming into the stands, you're more than welcome to go ahead and grab it and catch it and do whatever you want to," Granderson said. "Once you come onto the field of play, whether it's reaching over or actually stepping onto the field, obviously then the rule has been broken."
Granderson said he was not seeking any legal punishment. An Angels spokesman said the offender was ejected but there will be no legal involvement.
"I don't know how the stadium handles those different things, what the protocol happens to be," Granderson said. "I'm not going to do anything with it. I was able to continue to play the game, and that's fine with me."