Shaquille O'Neal joined his teammates for Thursday's flight to New York in advance of Friday's Game 3 of an Eastern Conference quarterfinal series with the New York Knicks.

During Wednesday's practice at the Sports Authority Training Center in Waltham, Celtics coach Doc Rivers said that O'Neal's ability to travel would suggest he might be able to play again as early as Sunday's Game 4 in New York.

"If he's closer to playing -- you know how we've done it -- if you see him on the trip he's really close," Rivers said Wednesday.