A lot will depend on who is acquired between now and April 1st.
Given the current roster, though...
I don't see Freddy Galvis in the Blanco role. If Galvis stays on the roster (e.g., is not traded), then he's the shortstop. I don't see how Kapler can relegate Freddy to bench status (established starter, heading into his free agent off-season, fan favorite). That's a ridiculous burden to dump on a rookie manager. Given that, I pretty much expect Galvis to be traded this winter.
So who fills that utility niche in 2018? Pedro Florimon, perhaps, if he opts to stay in the organization after a probable outright assignment in the next couple of weeks (he'll become a minor-league free agent if/when outrighted)? Jes Valentin? Eliezer Alvarez? Somebody not currently in the organization?