Prigioni sprained his right ankle at the end of the first quarter in Wednesday's regular-season finale against the Atlanta Hawks.
The Knicks said X-rays on Prigioni's ankle came back negative. Knicks coach Mike Woodson said after the game that he was unsure whether Prigioni would be available Saturday against the rival Celtics.
If Prigioni can't play, Woodson said he may insert rookie Chris Copeland into the starting five.
This alignment would allow Anthony to remain at power forward, where he has exploited mismatches for most of the regular season.
"We're definitely going to miss Pablo but it can't change nothing because it's the playoffs,'' Felton said. "We got to perform. We're definitely going to miss Pablo. And hopefully we'll get him back the second game. Maybe the first game and a miracle happens.''
Prigioni went down with 51 seconds left in the first quarter. He appeared to roll his ankle on a jump-stop near the rim.
The 36-year-old Prigioni has started the past 18 games, and was a key cog during the Knicks' 13-game winning streak late in the regular season.
Ian Begley is a regular contributor to ESPNNewYork.com.