Which QB should I start this week?

I have Palmer (100% starting), Garrard, Sanchez, and Bradford (100% not starting - 1st NFL game as a rookie :S) SO it comes down to who to start in my 2nd QB slot between Sanchez (vs. Bal) or Garrard (vs. Den). I'm leaning toward Garrard right now, but I really just don't know. What do you all think?