The new guys got a few games to get acclimated and fill in for injured Celtics but now that Delonte West and Big Baby are back in the lineup, it seems clear who Doc's preferred 8-9 man rotation is. Of course there is the big 4 of Rondo, Allen, Pierce, and Garnett. Krstic is holding down the fort for Shaq for the time being but will slide back into the backup big position. Glen Davis is the finishing big and super sub while Delonte West and Jeff Green will pick up the bulk of the remaining backup minutes.
It fits well because while the starters are very ingrained in their particular positions (with good reason), the backups are very versatile. West can play the point or slide over to shooting guard. Green is quick enough to guard 2's for a short period of time but long enough to play power forward in a James Posey role. Big Baby backs up KG and plays along side him at the end of games. Krstic is always going to be a center, but he gives us a different look from Shaq since he can hit that midrange jumper.
We might see a little bit of Carlos Arroyo in the rotation but I think he's really more insurance for Delonte and Rondo at this point. I know that Ainge keeps preaching that Jermaine O'Neal is going to be back for the playoffs, but I don't think I'm alone in my "I'll believe it when I see it" stance. My quick take on him is that even if he came back in early April, it might not be till the 2nd round when he got back into game shape and could contribute in any meaningful way.
So I suppose the only discussion left is who will be left off the playoff roster. Like the regular season, Doc can dress 12 players and 3 will be inactive. Avery Bradley is a no-brainer and injuries could very well dictate the other two spots. But in that fantastical world of "if everyone is healthy" I don't know if you deactivate Pavlovic or Wafer or Murphy. I suppose it just depends on the matchups for each series.