Trying times for Celtics

Considering the celebrations that seemingly came with Thursday's news that Celtics forward Kevin Garnett would be sidelined for a mere two weeks, one would think New Year's came to Boston 32 hours early.

Celtics president of basketball operations Danny Ainge's declaration that Garnett has a strained right calf calmed fears from 20 hours earlier, when pundits from coast to coast made the, um, knee-jerk reaction that Garnett might have reinjured his surgically repaired right knee and that his time away from the court would be measured in months instead of weeks.

Even after Celtics coach Doc Rivers hinted following Wednesday's loss to the Detroit Pistons that the team was confident it was merely a muscle injury in Garnett's right leg, a cryptic suggestion that it was a region above his ankle but below his knee left room for skepticism.

But Ainge, making his weekly appearance on Boston sports radio WEEI on Thursday afternoon, said an MRI taken that morning confirmed the strained calf prognosis and went so far as to suggest that Garnett "may be out for a couple of weeks, at the most." Ainge added that such a timetable might be "on the conservative side."

The Celtics have rarely undersold a player's return date. Quite the opposite, players have been given extra time to make sure they are healthy before being thrust back onto the floor, even in the face of mounting injuries.

Jermaine O'Neal initially was given a two- to three-week window to deal with left knee soreness in early November, but ultimately missed nearly two months before returning on Christmas. Rajon Rondo got a one- to two-week diagnosis after spraining his left ankle against the New York Knicks on Dec. 15, but Ainge expressed hesitation Thursday about whether Rondo is ready to get back on the floor after missing the past six games.

As the new year approaches, the Celtics are set to start an intimidating January slate. Following a New Year's Eve visit from the New Orleans Hornets, the Celtics will play five games in seven days, a span that includes trips to Toronto and Chicago.

After not playing more than 14 games in a month to start the 2010-11 season, the Celtics will play 16 games in January, culminating with a four-game western trip that includes tilts with the Portland Trail Blazers, Phoenix Suns and Los Angeles Lakers to wrap up the month.

The Celtics clearly could use a full complement of players, allowing them to keep rookies Avery Bradley and Luke Harangody in suit coats.

Instead, Harangody found himself playing a post role typically reserved for Garnett on Wednesday night against the Pistons, while Bradley is learning how to be an NBA point guard on the fly in Rondo's absence.

The loss of Garnett will certainly hurt the Celtics in the short term; they'll particularly miss his quarterbacking skills on defense. The numbers drive this home: The Celtics are plus-14.4 in point differential per 48 minutes when Garnett is on the court this season; they're minus-3.7 when he's not. Offensively, Boston's field goal percentage goes from 51.8 percent with Garnett to 46.9 without him.

The Celtics, however, have weathered storms without Garnett before. They've played 49 regular-season games without him during the new Big Three era, maintaining a .673 winning percentage during that time. But as Rivers noted after Wednesday's game, Garnett isn't the only one absent this time around.

"Usually without Kevin, we have everyone else," Rivers said. "As Paul [Pierce] said, 'How many more can we take?' If Kevin misses games, we're without Kevin, Rondo, [Kendrick Perkins], Delonte [West]. The list is getting really long. I don't think anyone will feel bad for us."

Boston is likely to use Glen Davis in the starting lineup (even if the Celtics would prefer to keep him in the sixth man role he's thrived in this season). Boston brought in the O'Neal brothers (as Rivers likes to call them) -- Shaquille and Jermaine -- to bolster the frontcourt. In fact, Boston is so comfortable with its depth there (even with rookie center Semih Erden battling a stomach bug that forced him to miss all three games on the holiday road trip) that Ainge said he's more worried about Boston's backcourt.

"I'm more concerned about our backcourt with Delonte and Rajon down, and Nate [Robinson] not quite 100 percent," Ainge said Thursday. "Again, with [heightened minutes for Ray Allen and Paul Pierce], we need Avery and Von [Wafer] and Luke to step up and contribute."

Therein lies the greatest challenge for Boston moving forward. When injuries have cropped up, Rivers has leaned on Allen and Pierce to fill the voids, giving them significant minutes with the second unit, particularly in big games.

The Celtics don't want to run their aging veterans into the ground in January when the ultimate goal is sought in June. But the trickle-down effect of all the injuries already has been felt.

Inconsistent guard play reared its ugly head as Boston dropped two of three on its just-completed trip. The Celtics, averaging better than 50 percent shooting for the season, shot a mere 34.6 percent in losing to the Magic on Christmas Day, then turned the ball over a season-high 21 times against the Pistons.

Rondo is getting closer to a return, and if the Celtics want to give him more rest, they'll likely have to chain him down when Chris Paul and the Hornets visit Friday. But can the whole team get -- and, more importantly, stay -- healthy? This is the sort of injury wall Boston hit last season before stumbling through the final 54 games of the season (playing .500 ball in that stretch).

The Celtics hang their hats on the fact that they ripped off a 14-game winning streak in the face of mounting injuries this month. If -- and that's a monster "if" -- they can survive the next two weeks with as many as three starters sidelined (Rondo, Garnett and Perkins), there's great hope about what this team is capable of when it's at full strength.

It simply has to get there. And while there's no guarantee that will happen, the outlook is better than it seemed Wednesday night.

Chris Forsberg is the Celtics reporter for ESPNBoston.com. Follow him on Twitter.