How about this deal with Denver:
Celts get - Javale McGee and Wilson Chandler
Denver gets - Paul Pierce, Avery Bradley and our 16th pick in this year's draft.
Celts benefit by getting an actual center (forgot those existed in the NBA). Also Green, Rondo and McGee would be a fun up and down team and KG can finally go back to the 4.
Denver gets an experienced veteran in Pierce, a good 2 defender in Bradley, cap relief by unloading Chanlder and McGee and a decent 1st round pick.