The Celtics were left without forward Robert Williams III for the second consecutive game on Wednesday night.
Boston coach Ime Udoka said Williams was still experiencing soreness on Wednesday and the team decided to hold him out of the team's Game 5.
"The swelling went down and that's why we were hopeful for tonight, due to the swelling getting better over the last few days,"
Udoka said of Williams, who was listed as questionable. "But he had some soreness, so we'll be overly cautious coming off the surgery.
Williams returned from a torn meniscus in his left knee in Game 3 of Boston's first-round playoff series victory over the Brooklyn Nets.