Found this interesting bit at reds.com:
Hanigan's backup, Devin Mesoraco, struggled and was demoted in late August for 10 days. Mesoraco still has some growing to do at the position, but he remains in the club's plans. He did a good job mainly working with Bailey and Leake, but others weren't comfortable with him behind the plate, namely Chapman. The Reds were fortunate that Minor League signee Navarro stepped up when Mesoraco faltered. Navarro could be part of the depth if he's retained.
Not that it can't change, but the fact that Chapman isn't comfortable with Mez is apparently limiting his playing time. You'd think that a move to the rotation for Chapman could also mean increased playing time for Mez. I predict more gridlock and status quo on this issue. Chapman is too good and so is Hanigan in the current configuration.