Who expected the Marlins to do squat?? There's NO pressure to be a great team when you're NOT a great team. The Marlins are merely playing great because the expectation is low.
OTOH, the Yankees....are expected to win ALL THE TIME, aren't they?
So it seems to me the pressure is all on the Yankees. But you said it was the Marlins who had the pressure. I think the Marlins have been playing quite loose.