The three biggest holes for the celtics are:
1. Defensive stopper on the perimeter
2. Back up point guard with a jumpshot, and must be adequate in utilizing the pick and roll
3. A back up bigman taller than 6-8, who can at least block shots
I think the Celtics should try to reach out to Theo Papaloukas, he is a basketball genius, a proven winner, great in the clutch, can play both guard spots, plus he can shoot (at least better than Rondo) and defend.
Carlos Arroyo , a free agent would complement Rondo well. They are exact opposites of each other. The former, a shoot first, take charge point guard, while the latter a defensive minded, pass first, second and third point guard.
At center, I hope they can trade for David Lee, Jeff Foster, or sign Kurt Thomas, Alonzo Mourning.
For hole no.1, if they can't get Posey, they can try Quinton Ross, Ruben Patterson, Maurice Evans or they can re sign Tony Allen, Since Pietrus went to Orlando, playing him and Bogans can be redundant, the celtics can explore that possibility too.