On Monday, Van Gundy said he was bothered by the number of times Wallace and Cleveland Cavaliers point guard Mo Williams dropped to the floor in Game 3 of the Eastern Conference finals against the Magic. He said the pair "fell down more than a baby learning to walk."
Wallace, a four-time defensive player of the year and one of the league's most intimidating players, took offense to Van Gundy's remarks.
Speaking at a shootaround Tuesday, Wallace suggested that Van Gundy "come out here and do something about it" or shut up, adding an expletive for emphasis. "Whatever he says isn't going to change the way I play defense or the way we play defense. It is what it is."
LeBron James was amused by Van Gundy's comment about his teammate and was willing to wager the Magic's verbose coach wouldn't share his belief with Wallace.
"You guys know how Stan is, man." James said. "We all know Ben Wallace has never been a flopper. He'll never be a flopper and if you think he's a flopper, I bet you won't tell him to his face that's he's a flopper. I damn sure know you won't tell him to his face. I know that for a fact."
About 90 minutes before Game 4, Van Gundy said he wasn't bothered by Wallace's response to his comments and that he was just trying to explain that Cleveland isn't the only team with complaints.
"I had some plays I commented on," Van Gundy said. "Ben took offense, that's fine. I don't really care."
Van Gundy made the same claims about O'Neal in March, saying he flopped while guarding Magic center Dwight Howard. O'Neal played for Van Gundy in Miami for parts of two seasons.
Williams said he was unaware of Van Gundy's comments.
"That's what he said?" Williams asked before deciding not to escalate the feud. "OK. I play basketball. I don't talk to coaches. That doesn't help us win any basketball games."
Cleveland coach Mike Brown also claimed he didn't hear Van Gundy's reference of Wallace.
"Stan called Ben a flopper?" he said. "That's great. I guess I'll go tell Ben."
Also Tuesday, the league rescinded the flagrant foul called on Magic guard Anthony Johnson for elbowing Williams in the head on a drive in Sunday night's game. Williams, who was called for a blocking foul on the play, needed four stitches to close two gashes around his left eye for the blow both he and teammate LeBron James felt was intentional.