"Jermaine O'Neal won't know until this morning — perhaps not until gametime tonight against Philadelphia — if he is ready to play for the first time in 18 games.

But the Celtics backup center got what he sorely needed yesterday, a practice with contact, banging against Shaquille O'Neal and Kevin Garnett.

Both players struggled to get off shots against the other O'Neal — in Garnett's case a 20-foot airball. That much he can contribute right now.

"I can alter some shots and get some rebounds," he said after the open practice, held in front of a group of sponsors.

"(Defense is) something you don't need chemistry or rhythm for. That's something Doc (Rivers) is expecting from me. I'm looking forward to that, because I can do that."

Just don't ask him to have instant chemistry or conditioning. Though O'Neal said his left knee feels good, anything else is going to take time."