Why mess around with a guy who has been doing pretty well and is just getting his feet wet in the major leagues? Why not move the guy who was a 2B back to a position he's at least very familiar with?
If you look at total performance this season, Jake Burger has earned the starting 3B job from Moncada for now. So if you want to give Moncada a chance for regular ABs to see if he can get out of his funk you can plug him into the existing hole at 2B, or you can send him to Charlotte to play 3B every day until he gets his act together. The change of scenery (either to 2B or Charlotte) may be what he needs. And if he truly is injured like some here are saying, then he belongs on the IL not at 3B or taking up a spot on the bench.