Actually the Raiders have this other virtually unknown running back named McFadden. He's a first round pick who's averaging a very modest 5.3 ypc. Fyi, these three sentences have a slight tinge of sarcasm.
Now as to the question. You are definitely going to pick up Fargas for a number of reasons. 1) His bye week is over, 2) Faulk is more of a receiving back and I doubt he'll get 2 TDs in a game again 3) Faulk has to split carries with Maloney, Morris, and LaMont Jordan 4) Fargas is the starter for the Raiders at this point and 5) Fargas is more talented than Faulk.