I take issue with this "it's been a quick rebuild" thing.
If "rebuild" means "get back to competing for a playoff spot," then yes, by all means.
My criteria is a little more stringent though. I won't consider the team "rebuilt" until they're relevant in any discussion of the post-season. Which, to me, means that, though they might not be considered an actual contender, they are regarded as a team with a chance of knocking off a contender, i.e. the sort of team a contender would not like to face on their way to the Finals (example would be the Grizzlies of the last few years, the Pacers a couple years back, and those Chicago teams that unfortunately could never stay healthy).
When they do finally reach that point, I'll only be truly satisfied with it if there seems to be a plausible avenue for taking yet another step toward genuine contention, and sustaining that level of success for the foreseeable future.
Yes, I have high standards. I'm OK with that.
I think the Celts are still a great distance from being "rebuilt," given all of that. It's a scrappy team that's been up and down due to deficiencies in talent and size, but they're well coached and deep. Nevertheless, I don't think they have a prayer in the post-season. This team is not built for playoff basketball.
All of which is fine. This rebuild only just began a couple years ago.
Anyway, I think this will be a quiet deadline, and the names most likely to move -- Ryan Anderson and Markieff Morris top the list for me -- don't seem like they'd help the Celts all that much.