The reason is, Manu and Barry will be taking up TP's score slack. Parker has almost no confidence and unless Pop tells him to continue shooting even if he is barely shooting 30%, I can not see him average what he did last year.
Why can't they trade him and another Spur for Marbury or someone close to that calibre? I know they won't, but I seriously do not have any confidence in Parker getting much better than he already is. Maybe I am wrong, hope I am, but so far, he has shown nothing at all this year.