"We'll be healthy sooner rather than later. We've just got to continue to fight, play hard, and find ways to win games."
Pierce scored a team-high 37 points while Rondo, despite being hurt, added 26 points, a game-high 10 assists, and 5 rebounds.
But the Bulls, wearing green for St. Patrick's Day, got 38 points from John Salmons (tying his career high), shot 53 percent from the field, and scored 58 points in the paint.
The Celtics fell to 9-6 without Kevin Garnett this season and are now 4 1/2 games behind Cleveland for first place in the Eastern Conference.
Celtics coach Doc Rivers was proud of the fight his beaten-up team showed.
"We look like a team with not enough players," Rivers said. "That happens. I was really happy with our guys."
The Celtics were already without Garnett (knee), Glen Davis (ankle), Brian Scalabrine (concussion), and Tony Allen (finger surgery). Eddie House returned to action despite a left ankle injury he suffered in Sunday's loss to Milwaukee and scored 13 points in 28 minutes.
But things got worse when Powe was lost in the first quarter to a sprained right knee. Powe, who banged knees with Chicago's Ben Gordon, will be evaluated in Boston today but doesn't expect to play tonight.
Rondo hurt his right ankle in the third quarter but he got it taped in the locker room and returned with 4:47 left in the period. An injury to his ankle recently caused Rondo to miss two games, and he was uncertain about his status tonight.
Allen hyperextended his right elbow late in the game and was uncertain about tonight as well.
When forward Mikki Moore fouled out with 11:17 remaining in the game, the Celtics were down to nine players. Pierce even played some center for the first time since he was at Inglewood (Calif.) High.
"There's that point where sometimes it's just bad luck for either one individual or one team," said Allen, who had 17 points and nailed four 3-pointers. "We have a team of professionals that make sure we stay healthy all the time. You have to listen to the body and definitely listen to the trainers."
Said Rondo, "Seems like every game someone's going down. People just have to step up and play through it."
