The Celtics could be without center Shaquille O'Neal for two weeks.

O'Neal, 38, missed Tuesday night's win against Detroit and Wednesday's contest against Milwaukee because of a knee injury.

"He's not gonna play," Celtics coach Doc Rivers said of O'Neal prior to Wednesday's game.

"I don't know if he'll even play on this trip coming up. We don't know yet, but obviously watching him move he didn't move very well today."

After Friday's home game against Chicago, Boston will travel to Oklahoma City, Dallas, Miami and Memphis before returning home to face Washington on Nov. 17.

"I'm just going by what I saw," Rivers said of O'Neal, who isn't expected to play on Friday.

O'Neal is averaging 8.7 points and 5.3 rebounds in three games.