Marlins catcher J.T. Realmuto: How good can he be?

From the Minor League Ball mailbag:

I remember reading a blurb you wrote about Marlins catcher JT Realmuto where you said he had the glove to play in the majors but at that point in time you only 79% trusted his bat.

Since the start of July though, he's been hitting over .300, shown surprising speed for a catcher, and he's both been stealing bases and hitting a pretty good amount of triples. He's also drawn some Jason Kendall comparisons in the process.

All of which begs the question, could you write up a prospect retrospective on JT Realmuto and give your analysis on whether his success is just about small sample size or if you feel he's honestly turned a corner and begun to come into his own as a major league player?---Charlie

Charlie's question came in a few days ago and Realmuto pitched into a mini-slump soon after, dropping his July numbers down. Overall J.T. hit .257/.286/.473 on the month, showing good power but not much patience.

Realmuto is hitting .252/.280/.402 overall on the season and now has a career .251/.279/.397 line in 315 big league at-bats. Ultimately the only real difference between July 2015 and the rest of his career is a spike in isolated power.

Here is what I wrote about him pre-season in the 2015 Baseball Prospect Book.

For the amount of hype this guy gets, you’d think he was the second coming of Johnny Bench. Now, don’t get me wrong, Realmuto is a very good prospect and the grade reflects that, but I think the paucity of catching prospects sometimes creates unrealistic expectations. The positives: he has developed into an excellent defensive catcher, mobile, reliable, accurate and strong arm, good leadership skills. All that will get him a big league job but the bat will determine if he starts regularly. He did hit well last year, boosting his power and maintaining his strike zone judgment. However, he was repeating the league, and he hit poorly in 2013 and 2012. The explanation that "he was working on his defense" sounds like special pleading to me. That said, catchers sometimes have unusual development curves for both good and ill, and it would not be unprecedented for a guy like this to take a step forward as he moves into his mature years. The bottom line: Realmuto is a very solid prospect who may very well become a long-term regular catcher and a very good one. Just beware of over-hype and the risks inherent in catching prospects. Grade B.

I would not change any of that based on what has happened in 2015.

Realmuto looks like a low batting average, low OBP hitter who has just enough power to play but not quite enough to be a lineup mainstay. As noted, catchers sometimes develop in odd ways and it is plausible that Realmuto could grow past his current level of offensive production and have a Yadier Molina-style outburst in his late 20s. His glovework is good enough to keep him employed for years even if the hitting surge doesn't happen.

Even if we accept a positive outlook on his bat, I don't think Realmuto comps well with Jason Kendall. J.T. is taller and stockier on a physical basis, and Kendall was a much better hitter at a young age than Realmuto is. Kendall hit .300/.372/.401 in the major leagues at age 22 and .294/.391/.434 at age 23. Realmuto is already 24 and hasn't come anywhere close to that type of hitting skill for any length of time.

That doesn't mean he's a bad player of course. As long as his body holds up, Realmuto will make a lot of money as a defense-oriented catcher with occasional power, with a non-zero chance to grow beyond that in his peak years.

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