Pierce

ATLANTA — The NBA apparently views its game films very closely in the playoffs.

The Celtics’ Paul Pierce was fined $25,000 yesterday for “making a menacing gesture” during the fourth quarter of Saturday night’s Game Three loss in Atlanta, according to the NBA. The gesture, which is now being shown on YouTube.com and is known as “The B” can apparently be interpreted as being gang-related.

The incident occurred in the final minute of the game when the Hawks’ Al Horford walked by Pierce, who was sprawled on the floor, and woofed at the Celtics’ captain. Pierce rose to his feet, walked toward halfcourt, stared down Horford and flashed the sign with his right hand for less than two seconds. He was then pulled away by Brian Scalabrine.

Pierce refused to comment on the fine before last night’s Game Four but the Celtics clearly do not think it was warranted.

“He’ll appeal it and I think he’ll actually win the appeal. That’s my opinion. It’s behind us,” said coach Doc Rivers. “It’s silly. Our players have signs towards each other. It just happens and everybody is very sensitive about signs. I didn’t know that. I know now.”

Veteran guard Sam Cassell did not know of the fine. When told what the reason was, he said, “This league has changed a lot. Wow.”

Executive director of basketball operations Danny Ainge said he sees Pierce make the sign before every game, shaking his hand as he jogs out for introductions.

“Every game, he does blood, sweat and tears. That’s kind of his sign. It’s not anything related to anything. That’s what he does. Every single game during the introductions,” said Ainge.

Ainge was seen in an animated discussion with NBA commissioner David Stern a half hour before the game. Stern was later asked about the sign and the fine.

“I would say that the league is sending a message that says ‘You’re the best athletes in the world. Play the game. If you get baited, don’t take the bait. Let’s play. Let’s show what you’ve got, which happens to be the most extraordinary athletes playing a spectacular game. We’re not going to let it degenerate into something else. Period.’ ” he said.

Stern said that hand gestures and some things players say in prior eras can mean very different things today.

Rivers said he didn’t understand why the Hawks’ Horford wasn’t disciplined.

“He should have been fined,” said Rivers. “Horford should have been teched for taunting right on the spot. That’s clear.”

kmcnamar@projo.com