As the NBA season begins, one of the main storylines for the Celtics was about getting younger, healthier, and providing more depth on the bench, a key aspect of their 2008 championship run.
To do that, the Celtics made a decision to let futre Hall of Famer and three point specialist Ray Allen walk in free agency; he would then sign with the Miami Heat, the main contention for Boston out of the East. Boston let it be known that by letting Allen go, they invested in the 21-year old Bradley, the Celtics' first-round pick, selected 19th overall, in the 2010 NBA Draft.
The young shooting guard initially played a good backup role as the primary shooting guard behind Allen. But as Allen got hit with nagging injuries, Bradley saw more playing time, and better chemistry with point guard Rajon Rondo and the offense as a result. His ability as a lock down defender served Boston well later in the season and in the first part of the playoffs. It was when he went down with a shoulder injury that Boston's already thin depth took a hard hit.