I don't think he's used to playing on a team that plays the way the Celtics do. That is, sharing the ball, competing every night, not giving up on any possession, etc.
At times he looks lost out there because he seems to expect his teammates to act differently than they do (e.g. when they pass him the ball inside instead of just shooting it).
agree, i think it'll take him some getting used to, all we need him to do is play defense and work the boards, rondo will get him some easy shots when he is in there anyways
if he can accept his role on team and settle into celtics mindset, defense and do your job (picks & rebound) he will be fine, as of now he's behind "steamer" , jermaine and kg at center spot
still very early in season