In response to davidap's comment:
Forget Jefferson, forget Howard. Sign Oden at short money. It's time for the Celtics' luck to turn around. Watch Oden finally be healthy and emerge as the franchise center he should have been fresh out of Ohio State. Overpay for him, if necessary. Signing an injury risk and hoping for the best is the only way the Celtics will be able to add a quality center. Andrew Bynum fits this category too, but I think he'll still get huge dollars from somebody, probably Philadelphia which needs something to show for Andre Igoudala. The difference between Bynum and Oden is that Bynum already proved himself a top NBA cener when healthy. Oden has yet to sustain any kind of success at the professional level in large part because he can't stay on the court for more than a couple months at a time.
I don't believe that Oden will never be healthy for an entire season. Although, he is worth taking a chance on. Bynum is also very talented and probably the best center in the league when healthy. Just not sure if he will ever be healthy for an entire season. I don't know what is going to happen to Bynum for the remainder of his career.