Who is this guy and what has he done with Nathan Martorella?

In the estimation of many analysts, including our own Fish On First staff, Nathan Martorella was the No. 3 piece of the Luis Arraez trade package. He lacked the upside of Dillon Head and the well-rounded skill set of Jakob Marsee, but Martorella's hit tool still made him a meaningful addition to the Miami Marlins organization. "If he finds more loft and continues to show patience in the upper minors, he could contribute to the Marlins by 2025," Alex Carver wrote in the aftermath of the deal.

Martorella had prior Double-A experience as a San Diego Padres prospect and joined the Pensacola Blue Wahoos everyday lineup. He made a solid first impression during his debut series, collecting multiple hits in three of his first six Pensacola games with a .320/.370/.360 slash line.

That was back in early May. Martorella has only one multi-hit game since then. Very quietly, he's been in a lengthy, awful slump. What's gone wrong for the 23-year-old?

Martorella with AA San Antonio: 48 G, .264/.354/.404, 5 HR, 12.1 BB%, 15.0 K%, 110 wRC+

Martorella with AA Pensacola: 46 G, .169/.223/.221, 1 HR, 4.3 BB%, 19.7 K%, 33 wRC+

Yikes. The statistical similarities between him and recently DFA'd Tim Anderson are striking. Martorella's walk rate is one-third of what it previously was against Double-A competition and he isn't even slugging his own weight (listed at 224 pounds). Per FanGraphs, no position player who's starting regularly at any level of the Marlins org has a lower wRC+ than him.

It is not a matter of platoons for the left-handed hitter—he's been equally lousy vs. lefty and righty pitchers. In the aforementioned post-trade write-up, Carver noted Martorella's slightly concerning groundball rate, but that hasn't been the culprit either. His 38.0 GB% is lower than the Southern League average, so he's giving himself ample opportunities to produce runs on balls in the air.

Martorella is still demonstrating solid contact ability. The quality of that contact leaves a lot to be desired, though. His .204 BABIP is the lowest of any Marlins minor leaguer with a comparable number of plate appearances.

Your gut reaction to that stat might be to let Martorella off the hook as a victim of bad luck, but here are all the balls that he put into play during a recent series in Birmingham. He went 1-for-12 on these with the Barons defense exerting ordinary effort to record each out. Even when he got hittable pitches in favorable counts, he couldn't square the ball up.

As is the case with Nick Fortes in Miami, a player who's prone to popping the ball up will struggle in the BABIP department. In addition to swinging underneath the ball, Martorella is compounding this issue by arriving late, hence his propensity to pop out to third basemen in foul territory. Beyond the damage being done to his individual numbers, he's seldom making productive outs to benefit his team. No surprise, with Martorella regularly residing in the heart of their lineup, the Blue Wahoos have the Southern League's lowest-scoring offense. He has driven in only 10 runs since his acquisition.

I have not detected any meaningful changes in Martorella's swing mechanics over the course of the season: same deep crouch, same low hand position, same small stride. Rather, opponents seemingly took notice of how vulnerable he is against elevated pitches. Whether they feed him high fastballs or hang offspeed stuff by mistake, he's making outs or fouling them off.

Martorella will be heavily scrutinized by Marlins fans because of his inclusion in the Arraez trade, but any way you slice it, he's in a low-stakes situation right now. There is no rush to get him to the big leagues in 2024. He isn't even eligible for the Rule 5 Draft until after the 2025 season. Time is on his side to solve this problem.

Nonetheless, it's discouraging to see such a stark contrast between his Marlins and non-Marlins splits. Long term, as a first baseman/left fielder, he'll need to markedly improve both his power and plate discipline to make a major league impact.

Interested in learning more about the Miami Marlins' top prospects? Check out our comprehensive top prospects list that includes up-to-date stats, articles and videos about every prospect, scouting reports, and more!