The Diamondbacks could be in the look for an upgrade behind the dish, or at least defensively over incumbent starter Welington Castillo. Castillo is off of a 2.4 bWAR/1.7 fWAR season, which on the surface is acceptable. However, one area Castillo struggled in is pitch framing, despite a strong defensive season overall. Castillo's pitch framing cost the team 3.2 runs over the season. While it isn't alarmingly bad, with a young pitching staff a good framer is very critical.
The best pitch framer on the free agent market was Jason Castro, who just recently signed a 3-year deal with the Minnesota Twins.