Celtics General Manager Danny Ainge said that whether Shaquille O'Neal returns for the regular season or waits until the playoffs is uncertain.

Ainge watched O'Neal go through a private workout at the Celtics practice facility on Wednesday. O'Neal is trying to recover from a sore right Achilles tendon.

"It could be a week or two weeks," said Ainge. "I watched him work out, and he’s starting to do things on the court. We’re just still not sure of when he’s going to come back."