I would expect Mauer to stay relatively healthy at 1B, but if he goes down, I'd assume Park goes to first full time, Sano plays more DH, and then Kepler might get his shot. Or maybe Arcia just increases his playing time and they call up Vargas. Either way, the Twins seem pretty committed to Sano in the outfield full time this year, so arguing for a scenario where Sano is at 1B (for this season) is pretty unrealistic.