WALTHAM, Mass. -- Celtics center Shaquille O'Neal did not address the media, hoping to test his sprained right calf the next couple days before that happens, but did appear on the court briefly Thursday before the start of Boston's practice session at the Sports Authority Training Center at HealthPoint.

O'Neal got up some shots, then retreated to the locker room with his teammates to watch film. Celtics coach Doc Rivers said his team will simply hold a walkthrough Thursday as part of on-court activity before ramping up Friday, which will provide O'Neal's first real test with eyes towards getting him back on the floor for Game 1 against the New York Knicks on Sunday night.

Rivers remains confident O'Neal will be ready to go when Boston tips off postseason play.

"I do [think Shaq will play in Game 1], I can't guarantee that," said Rivers. "He's going to do a little bit today. We're not going to do enough -- we're going to walk through stuff so I could do today -- but [Friday] and [Saturday] are the big days for Shaq. He's going to try to get through practice and see what we can do."