One thing is certain about Boston Celtics' point guard Rajon Rondo's injury: he'll be sidelined with a sprained left ankle.

How long? Well, it's probably going to be at least a week. Maybe longer.

Rondo was helped off the court after he hurt his ankle early in the fourth quarter of Wednesday night's 118-116 win over the New York Knicks. He returned and finished the game, then said afterward he expected to play against the Atlanta Hawks on Thursday night.

But general manager Danny Ainge said on WEEI-AM on Thursday that Rondo's ankle was swollen after the game and will need "a couple of weeks, anyway." Celtics spokesman Jeff Twiss clarified that no official timetable had been set.

YAO BREAKS ANKLE: Yao Ming has a stress fracture in his left ankle and the Houston Rockets said there is no timetable for the return of the 7-foot-6 center whose NBA career may be in serious jeopardy after a series of injuries.

Yao has been out since Nov. 10 with what had been called a bone bruise in the same ankle. An MRI performed Thursday revealed the stress fracture.

Yao, a seven-time All-Star, sat out last season after surgery to repair his broken left foot. The Rockets said his current injury is related to the old one, and was discovered during his current rehabilitation.

NOAH OUT: Chicago Bulls center Joakim Noah will miss the next eight to 10 weeks after having surgery on his right hand to repair a torn ligament.

The team said Noah had successful surgery on Thursday morning to repair the ulnar collateral ligament, which is the band of tissue attached to the middle joint of the thumb. He was hurt during Chicago's win at Sacramento on Nov. 27. Bulls athletic trainer Fred Tedeschi said surgery now avoids a more risky procedure later.