The Brewers starting catcher is Jonathan Lucroy. That is, of course, until he is traded. And make no mistake, he will be traded. That's just an inevitability. When that happens, the leading candidate to take over the majority of starts behind the plate is Martin Maldonado. He's been a back-up for his entire major league career. And while the ceiling is likely rather modest, I can't help but be intrigued by his potential.
I don't think many people question his defensive acumen. He's typically been excellent at receiving, pitch framing, blocking balls in the dirt, and he has an outstanding throwing arm. However last year something happened that kind of shocked me. When Lucroy broke his toe, Maldonado caught most of those games and he looked lost at times. He had trouble blocking pitches and he was horrible offensively.
It was recently revealed that Maldonado was dealing with a "family scare." The details were not made public--it's really none of our business--but it sounds like it was pretty serious. Being thrust into a full time role and dealing with a family matter seems like it would be a lot to take on at once. Perhaps that really is what lead to his early struggles. Overall he was still excellent defensively (6 DRS) and hit better--though still not great--in the second half (196/263/273 vs 231/311/319). It's just so hard to say because we're dealing with small sample sizes and, admittedly, arbitrary endpoints.
We should hope that his struggles last year were an isolated occurrence though. Because if he can even hit at a near league average level, he could legitimately be a 2-3 win catcher thanks to his defense. He's hit at that level twice in his career: 2012 (256 PA, 97 wRC+) and 2014 (126 PA, 96 wRC+). Again, the big problem here is that we're dealing with small samples. Just because he hit 96 wRC+ in a back-up role, doesn't mean he could do it in an expanded role. And we can't ignore that he was awful in 2013 (202 PA, 38 wRC+) and last year (256 PA, 53 wRC+).
But let's just focus on the positives here. If, and yes it's a big if at this point, but if he can provide near league average offensive there's every chance he could be a 2+ WAR catcher. In 2012 when he did it in 78 games he was worth 1.3 fWAR. In 2014 when he did it in 52 games he was worth 0.7 fWAR. Increase the work load to a full season of starts and I don't think it's out of line to assume he could be worth around 2-2.5 fWAR. That's a solid starting catcher.
Of course I'm not suggesting this is going to happen. I'm not even suggesting it's a likely outcome. I'll even hedge and say it's probably an unlikely outcome. But it's not impossible. I think sooner or later Maldonado is going to take over full time duties. How long that lasts depends partly on when Lucroy is traded as well as how quickly Jacob Nottingham develops. But if he hits well enough, Maldonado could make a case to remain as a regular at the position--though not necessarily with the Brewers.
Statistics courtesy of FanGraphs