It's not too difficult to guess his form at any particular moment if you've followed his career very closely. In this case, I'm pretty sure he started this Giro very far from a peak. He said he didn't feel great in the Etna stage, so the question is, could he have gained all that much fitness by tomorrow? My guess is that he is fit enough to keep up with most, but someone like Landa in really good form would be able to drop him. Of course, it's only a guess in both cases. We don't really know how good Landa is feeling either.