Knicks coach Mike D'Antoni made the expected announcement before Tuesday night's game and said he didn't know if the starting point guard, who has a sore left knee, would be ready for Game 3 of the best-of-seven, first-round series in New York on Friday night.
D'Antoni said he had no plans to change the offense with third-year pro Toney Douglas starting for Billups.
Billups was hurt late in Boston's 87-85 victory Sunday night when his leg buckled. He limped off the court with 51 seconds left and didn't return. He didn't practice with the team on Monday.