Volquez's spot was already filled by the signing of Gomez. Balentien and Miles' spots were filled by Nix and Cairo. So, even if Francisco goes down to AAA to clear space for Leake on the 25-man roster, someone else will have to get bounced off the 40-man roster as well.
Will be interesting to see who gets removed. The most likely candidates, if you ask me, include Cairo, Nix, Lincoln, Fisher and Viola. There could also be a surprise deal in the works, involving someone like Maloney, Lecure, Sutton or Valaika. We'll see what shakes down soon enough.