The return of Garnett, who had been expected to miss two to three weeks, has been extended.
"Kevin will be out longer than the Milwaukee game [Sunday]," coach Doc Rivers said. "I would say Kevin, maybe the end of the following week, at the earliest - maybe San Antonio, maybe Memphis [March 21].
"We'll probably be down to 10 [players] for this whole week. [Davis] and Rondo are out and will be out for probably the next couple games, maybe the next week. I actually made the comment [Sunday] that Rondo would be ready for Wednesday; I think we were wrong."
As vulnerable as the Celtics appear at point guard, they have three available. Eddie House likely will start against the Heat; Rivers second-guessed himself for starting Stephon Marbury against Orlando. Gabe Pruitt, whose development made Sam Cassell expendable, is also a possibility.
In any case, Rivers plans to limit the playing time of Ray Allen and Paul Pierce, which means J.R. Giddens, Bill Walker, and Pruitt will be in the game plan.
"It was different circumstances, because injuries happened either during the game or right before the game," Rivers said. "So it was tough to plan for it. But I still want to keep their minutes down, even in a time of crisis."
Rivers is not exaggerating much by calling this a crisis. The Celtics concluded the Magic game with nine available players (Leon Powe fouled out), illustrating their vulnerability.
But Rivers is portraying the situation positively.
"We just have to find ways to win games," he said. "This is a growth period for our team and, clearly, we want to win the games.
"But we have an opportunity to grow our team in this little stretch and get them closer together and get them all understanding how hard the work is going to be to win the title. And, then, when everybody comes back, in the long run, I think this might make us a better team.
"Every season is different, every challenge is different. It's good for all of us, even though we don't like going through it.
