He was honest about it. Jermaine O'Neal has been out so long that he couldn't remember the last time he practiced. "I couldn't even remember the last time I got on the team bus,'' he said with a smile yesterday. The last time he played a game for the Celtics was Jan. 12, more than two months ago. He has been rehabbing after undergoing arthroscopic surgery on his left knee and has been sidelined for 55 of the Celtics' 73 games this season.