Shaquille O'Neal didn't practice on Monday and will not play against the Cavaliers on Tuesday night.

It will be the second straight game that O'Neal has missed, following Boston's loss to Washington on Saturday.

"It's not a serious injury," coach Doc Rivers said, "but he's also 38 years old and we're going to be very cautious."

The Celtics will begin a four-game road trip on Thursday night in Portland and Rivers believes O'Neal will be able to play in one or two of those games.