Don't forget that Amare asked for KT so that he wouldn't have to bang away with the big guys. With a surgically repaired knee, he is probably even less inclined to want to do that for a season.
Diaw did a nice job against some not so great centers, but we still got badly outrebounded and outscored inside. Amare will change that, but KT will be the starting center, if he doesn't get traded. Diaw will come in with Barbosa when Nash goes out because Barbs doesn't set up the others.
I would trade (not give away) Barbs or Jones for a good backup PG.