I think if anything we will be better next year. We lost our sixth man before the season started (Green). We lost our opening day starting center (JO). We lost our first big off the bench at the time (Wilcox). In the playoffs we lost our starting 2 (Bradley). Due to a shortened season we are playing with a hobbled Pierce and Ray.
I'm not saying next year will be injury free, but with a normal regular season and hopefully some luck our team will make it to the playoffs more intact than it is now.
The two things that effect if a team improves or gets worse are 1. Who left vs who has been brought in. 2. Young player improvement vs Old player decline. I expect both these things to be positive for the Celtics.
1. Here are my expectations for Roster turnover:
Leaving: Dooling, Hollins, Pietrus, Pavlovic, Williams, Daniels
Joining: 1st round pick, 1st round pick, Jeff Green, Wilcox, One free agent at about $4-8 MM (depending on cost of other contracts), vet min free agent maybe one from group above
Those coming in at least on paper are much better than the role players leaving. This is assuming we bring KG and Bass back. This is also assuming we keep Ray or replace him with a bench player capable of scoring.
2. Players getting better: Rondo, Bradley, Moore, JJJ, Stiemsma
Players getting worse: Pierce, Garnett, Ray.
Again I think this is another positive. Garnett looked rejuvinated playing the 5 plus with less injuries I expect Doc to further cut his minutes, which could help him stay at the same level. Pierce's game doesn't rely on athletecism so his decline shouldn't be awful. Ray has been playing hurt most of the year and should be fully healthy and rested scoring off the bench. Rondo has improved his shot this year and this improvement should continue. Bradley showed us a glimpse of what he can be and with his youth you have to believe he improves. Moore showed on a limited basis that he can score in the league, I expect him to get more backup 1 minutes next year. JJJ is by all accounts a hard working kid, next year he will come in bigger and stronger with a better grasp of the system and doc more willing to give him a chance.
Overall I think it isn't a stretch to say the Celtics will be even better next year.