CELTIC NOTES

Paul Pierce practiced yesterday and said he was ready to play today, despite a variety of nagging injuries. Pierce, who sprained an ankle late in Game 2 of this series, left Game 3 on Friday with a muscle strain in the back of his right leg.

“If we ever thought we were putting Paul at risk by playing him, of course we wouldn’t do that,” Celtics coach Jim O’Brien said. “But Paul wants to play and there’s no reason physically why he shouldn’t.”

Added Pierce: “I’ll probably have it wrapped and wear a brace, but I’ll be OK. This is the playoffs. No one is going to be truly 100 percent every night. This isn’t an issue for me.”

* The NBA confirmed yesterday Celtic forward Antoine Walker will face an investigation by the league and Boston police after an altercation with Celtic season-ticket holder Stewart Berg.

Berg, who heckled Walker throughout the game, claimed afterward that he was “attacked” by Walker and “hit in the face.” The Celtics have already said they will revoke Berg’s tickets.

“I’m not going to talk about that ever again,” Walker said yesterday. Asked if he worried that the NBA might discipline him for the alleged confrontation, Walker repeated, “I’m not going to talk about that ever again.”