Rondo, who easily leads the NBA with 13.8 assists per game, has missed the last six contests with an ankle injury. While he had originally been targeting Friday for a possible return, the point guard may not be back on the court until 2011.
Boston (24-6) had still managed a 7-2 record this season with Rondo out due to various ailments before Wednesday, when Garnett's departure had a big impact in a 104-92 loss at Detroit. Untouched by any defenders on the play, Garnett injured his right leg on a dunk late in the first quarter.
The Celtics were relieved to hear he has only a strained right calf and not a problem with his surgically repaired right knee. General manager Danny Ainge told WEEI radio on Thursday that he expects the injury to "keep him out for a couple of weeks at the most."
Since the beginning of 2008-09, the Celtics are 112-44 (.718) with Garnett and 24-14 (.632) without him in the regular season, but their lackluster performance against the Pistons may not be the best indicator.
"I think Kevin's injury took a lot of wind out of our players, because we originally thought the injury was a lot more severe than it turned out to be," coach Doc Rivers said. "I think there was a while there where our minds weren't where we needed them to be."
Thanks in part to Garnett, the Celtics are typically focused on the defensive end. Boston has allowed 88.7 points per game during a 15-2 stretch since Nov. 22, with the Pistons posting the second-highest total of any opponent.
Over that same span, the Hornets (18-14) have gone 7-13, quickly spoiling their 11-1 start. They scored 100 or more points five times in their first 12 games, but have done it only three times since.
New Orleans may also be without its starting power forward after David West twisted his left ankle late in the first half during Wednesday's 103-88 home loss to the Los Angeles Lakers. West played through the injury but finished with eight points -- more than 10 below his season average.
The Hornets had won their previous four home games, but forward Trevor Ariza said his team "played really soft" against the Lakers.
"One day we're playing well and everybody is getting it going and the next day we could be somebody's little brother," Ariza said. "If we want to win and do something in this league, we can't be like that."
A road game against the Celtics isn't the easiest way to bounce back. New Orleans has lost seven straight away from home, matching its longest skid since early 2005, and Boston is 13-1 at home.
The Hornets beat the Celtics 93-85 at home without star point guard Chris Paul in the most recent meeting Feb. 10, but they've dropped their last three in Boston by at least 10 points each.