It isn't only a Joseph vs. De Colo issue. De Colo has been put in a suit while, Mills, a player that has been behind him in the rotation for month, is on the active roster. There is also Neal playing a lot while he truly sucks and an out of shape TMac being active.
I'm not saying these choices aren't the right ones. It's just that they aren't obvious and Pop should definitively spend a minute explaining to De Colo while he is inactive, even more that De Colo is known for his whining. That some basic coaching and I'm damn surprised Pop hasn't done that.