Well, it depends on what might be available and how much it will cost. If Rondo goes down mid season, a competent backup will cost alot more, since teams will know that the Celtics are desperate. Also, how long will it take for a midseason replacement to learn the offense?
I would give up BBD for the right player, such as Steve Blake. I'm a big BBD fan, but he is a luxury, not a necessity.