Marquis Daniels, who missed practice Wednesday due to illness and didn't appear to feel 100 percent before game time Thursday, started in Pierce's place. He scored 4 points in 31 minutes as the Cavs beat the Celtics 108-88.
Pierce will be out for the foreseeable future, Celtics coach Doc Rivers said before the game.
"No Paul [Thursday], and the next couple games, most likely," said Rivers, who added that Pierce, who participated in pregame warmups, was over the flu-like symptoms he was suffering from earlier in the week.
Pierce's injury occurred in the first half of a win over the Lakers last Thursday, and while he played two games after that he sat out Tuesday against the Knicks.
"We want to make sure it gets right," Rivers said. "It's one of those things where, if he gets hit again, he'll go back down that road. We want to make sure when he comes back he can play, and play at that Paul level we know."
The Celtics have approached all injuries cautiously all season, with an eye toward being as healthy as possible for the playoffs.
Daniels sounded congested as he sat at his locker stall before the game and did not dress until about an hour before the game.
"Marquis is going to give us what he has," Rivers said before the game. "I didn't want to tell him we need a warm body, because his body is warm. We'll see, you never know, sometimes guys come out and play great."
Asked whether Daniels would be limited, Rivers joked, "We'll play him the full 48."
Daniels started in place of Pierce Tuesday, scoring 14 points, including a pivotal layup in the final minutes to seal a 110-106 triumph at the TD Garden.
Chris Forsberg covers the Celtics for ESPNBoston.com.