Justin Poulin of CSL has this to say about Paul Pierce's lower numbers.
Paul Pierce has averaged only 14.6 PPG, 4.6 RPG, and 2.7 APG during this nine game span, which is far below career stats of 23 PPG, 6.4 RPG, and 3.9 APG. It has been the cream of the Celtics future crop that has risen to the top, making up for Pierce’s struggles and the some. Rajon Rondo has gone for 14 PPG, 9 APG, and 5.9 RPG with the highlight coming against the Pacers and a traditionally difficult match-up with TJ Ford – resulting in a triple-double effort with 16 points, 17 assists, and 13 rebounds. Paul Pierce has been shooting 38% while Rondo has been lights out at 60% despite the reasonable and obvious criticism that his jump shot still needs work. The return of Rondo’s floater has helped improve his scoring greatly as has the pace and anticipation he has exhibited while dribbling through paint.
Not only is Pierce less involved in setting up the offense, but his touches are way down as evidenced not only by less FGA (9.4 per game) but more notably FTA (3.4 per game) over the past nine games. During that time, Pierce has had only one game with double digit FTA as compared with six over the course of the first twelve games of this season. This fundamental shift is all about longevity, something that the national pundits doubt; success beyond the “three year window”. However, less FTA and fewer shots not only enhance the development of Rajon Rondo, but preserve Paul Pierce for the future as well.