Name one all star let alone superstar player ever willing to sign in Boston ... I'll wait.
They will have to daft their next star or trade for them like they did Pierce and Bird. It is why they have such huge lulls between relevance from Russell to Bird to Pierce. No one in a mostly black league wants to play in Boston because of stories of racism and unfair treatment from fans. Hell KG refused to be traded there to they got Allen first because of the city and stories he heard from other players. Bron, Melo, Wade, Dwight, and the like don't even have them on their radar as a destination. The only way Boton would ever get a marquee free agent is if the only teams that can make a play are Utah and Dallas, since Mormon country is shunned by most players and Dallas has never signed a quality free agent in its franchise existence; oh and Cleveland because Cleveland sucks to even visit