With Edwin Encarnacion in the majors and Todd Frazier and Brandon Waring in the minors, I'd so trade Juan Francisco while his stock is high.
I wouldn't be eager to. He's got high ceiling LH power to all fields, and that's huge in GAB. By the time the young LH sock in the Reds lineup is getting expensive, he might be ready. He may end up at 1B, who knows, so EdE or Frazier or whoever could stay at 3B.
The only other LH bat with a modicum of power in the system is Dorn, and he's really a line drive hitter. If Waring and Frazier both develop, those are the two who are redundant, in my opinion, given that they're both righty sticks.