Last year, when Ray Allen got hurt and Bradley took his starting position, a definite change could be seen in the play of this team. Bradley relieved Rondo of having to guard the best offensive player in the opponent's back court. His off the ball cuts and ability to run the floor and create turnovers with Rondo, helped make the offense less stagnant. His effect with the starters on the defensive end was staggering. They became one of the best defensive fives for the C's since 2008.
So when Doc sent Ray to the bench and started Bradley for good there was good reason for it. Ray was hurt and struggling, simultaneously. Bradley was playing well and he had obvious defensive advantages over Ray Allen and provided something different for the starting five. Namely, quickness, defense and a running game.
Thing is, as frustrated as some are with the play of this team, the removal of Pierce and inclusion of Green in the starting five isn't going to make this team better. Unlike the Allen-Bradley differences and dynamic that changed the team, the Green-Pierce difference isn't a positive one for the starters. Green brings nothing that Pierce doesn't already supply on a quantitative and qualitative basis. Simply put, you are taking out a great player to put in a mediocre role player.
Pierce is not having a Pierce at his best type of year. But he is still having an All-Star caliber year and benching him gains you nothing for a quality of basketball standpoint. And, it could lose Doc the locker room. Everyone in that locker room knows Pierce is not the problem with this team. Benching him, a stalwart of this era and the captain and locker room leader, for a guy who has a history of passivity and half heartedly giving an effort on many occasions, will not go over well with almost half the team, I am sure.
There is just nothing that shows that adding Green to the starting five will make him play better or the starting five play better. Pierce often plays with 3 or 4 bench players and none of those lineups show stats that make one believes Pierce or the bench will play better with Pierce coming off the bench.
So why risk it?
If you want to shake up a team, you don't bench its captain and one of the players giving a top effort for an overpaid mediocre role player that has a history of not showing up half the time. What you do is play guys giving you great effort the most minutes and have the GM trade one or two of the worst "effort" guys the heck out of town.