HELP!! RB playoff decisions!?

I was thinking of dropping barber and picking up pierre thomas, do you guys think this is a good decision? Barber is banged up and faces baltimore in week 16 and philly in week 17 and he shares carries with the rising tashard choice. Pierre Thomas is the primary back for the saints now that bush is out of hte picture. Thomas also faces detroit in week 16 and carolina in week 17. Your imput will be greatly appreciated... thanks