I've been very complimentary of C Darrien Miller this season. He's made improvements. He's handled the lion share of the catching duties. And, as I've said on numerous occasions, I watch roughly 2/3 the affiliate games each week. So, I have a pretty good handle on who is doing what and how they look.
You could have made an argument for Wes Clarke garnering consideration last season - he had the momentum and was trending - and, coming into this season you could have had some expectations he would put himself in serious contention for a call-up. But, the reality is, he just hasn't hit that well in Triple-A. The strikeout issues have re-surfaced. So, the logical thing to do there is give him more time. He's demonstrated he can improve at a level or excel, in the least, when given a season or so to adjust. However, up until this point, what we can factually say we have here is a streaky power hitter - certainly not a consistent hitter, however. There is absolutely zero need to rush a 40-Man spot considering the ongoing pitching carousel and wealth of options at 1B and DH. Simply consider, for example, Owen Miller returning to the Sounds line-up after being DFA'd and being thrown right to 1B and going 8-for-14 with 1 2B, 5 RBI, and only 1 K. I continue to be absolutely befuddled by this pipe dream that suddenly Wes Clarke is an MLB 40-Man catcher consideration for the Brewers.
Miller is nowhere near the level of play needed to be an MLB catcher - and, this isn't a criticism it's simply being honest. If you've watched him play the position. He is a nice Minor League player at this juncture - he has improved facets of his game - but is simply too flawed a defensive catchers at present. This doesn't even get into the thought exercise of extrapolating what he might experience facing MLB pitchers. He already has shown a continued propensity for pop up outs because his swing plane so often leaves a level plane. He is improving but he simply needs more time and experience (and off-seasons of continued committed work).
The Brewers catching scene right now is absolutely fine. You have Haase and Sanchez who have both proven more than adequate fill-in capacity at the MLB level. As mentioned above you have a well-perfoming Mejía AND, you now have a healthy Brian Navarreto. This is where, again, if you haven't seen these players play regularly and you're basing your opinions on something like wRC+ numbers solely you're missing the boat. Nava is 10x the MLB-caliber catcher than anyone in this discussion beyond the aforementioned Haase and Sanchez, obviously. IF the Brewers suddenly found themselves down both a Haase and a Sanchez they would simply accept Nava and Mejía with flawed MLB bats but (in Nava's case) a bat that has shown big hit capacity but both known for solid to plus defensive presence. At that juncture, they aren't going to be thinking: "Well, we could call up Damien and he could lean into some pitches and pray for some walks and hope the opposing team doesn't take advantage of his sub-average arm." We can simply enjoy he's improving at Double-A and go from there. Just consider the path of Nick Kahle in comparison to both Miller and Clarke behind the backstop. He is also nowhere near an MLB-level catcher but simply consider how he has been used in comparison.