Pirates Prospects reports. I doubt Inman has moved to the non-prospect stage where the Pirates will just bounce him between levels willy-nilly, so my guess here is that the Pirates want to move Inman up and see what they have, since he'll be eligible for the Rule 5 Draft after the season, and teams love to take live arms in the Rule 5 Draft and stick them in their bullpens.
Inman has excellent stuff, but he's hardly pitched at all, mostly because of elbow problems. When he has pitched, he's posted very strange numbers for someone who's supposed to be a power pitcher, generally doing a good job keeping runs off the board (thanks to a high ground-ball rate) but striking out very few batters. In any case, he's still an interesting pitcher, and he's 24; Class AA would seem to be a good place for him. Now let's see if he can stay healthy.