Boston started 0-3 without Piece and has ripped off four straight wins, including an 89-70 triumph versus New Jersey on Wednesday without Allen. Pierce scored 24 points, grabbed six rebounds and dished out five assists in that one and Brandon Bass finished with 15 points and 13 rebounds.
"Energy, play good defense, rebound, score when I get good opportunities. That's what I think my role is and that's what I'm going to try to bring every night," said Bass, who tied a career high with 13 boards.
Kevin Garnett added 14 points and 12 boards for the Celtics, who are 2-0 on a five-game homestand and are in the midst of playing eight of nine games at TD Garden. The C's are 3-0 as the host this season.
Allen is listed as questionable for Friday and is averaging 20.0 points and 2.8 assists this season. Pierce is fourth on the franchise's all-time games played list -- three behind current Rockets head coach Kevin McHale. He is also nearing Larry Bird for second in points scored in team annals.
Indiana, meanwhile, will put the finishing touches on a four-game road trip and is coming off Wednesday's 118-83 blowout loss to the red-hot Miami Heat. Heat superstar LeBron James did plenty of damage with 33 points, 13 assists and eight rebounds and fellow star Dwyane Wade was out with a foot issue.
Roy Hibbert ended with 16 points and 12 rebounds for the Pacers, who have lost two of three since a 3-0 start to the season. Tyler Hansbrough and George added 14 and 13 points, respectively, in a losing effort. Danny Granger ended with a season-low six points and David West posted nine.
"We were right there with them but then they went into second gear and unfortunately we were still in first," Hibbert said.
Pacers guard Lance Stephenson left the game with a sprained left ankle and is doubtful for tonight. Indiana was without center Jeff Foster (back) and forward Jeff Pendergraph (knee). Foster is probable and Pendergraph is listed as doubtful against the Celtics.
The Pacers lost three of four meetings with Boston a year ago and have dropped 11 of the previous 14 matchups in this series. Indiana is winless in seven straight contests at TD Garden and hopes the addition of West will make a difference against the Celtics.