LL’s Top 50 Mariners Prospects 2019: #5 - Justin Dunn

For better or worse, the 2018-19 Seattle Mariners’ offseason will go down as a seminal time in the franchise’s history. The season of change shipped several stalwarts to new homes, ranging from former Mariner draft picks to superstars acquired in past free agency periods or shrewd trades. That beloved group of players landed Seattle in the dreaded zone between the playoffs and a top-10 draft slot. Understandably, the front office assessed its situation and decided Robinson Canó, Alex Colomé, Nelson Cruz, Edwin Díaz, Ben Gamel, Guillermo Heredia, James Paxton, Jean Segura, Denard Span, Nick Vincent, and Mike Zunino were all useful pieces who now belong to a past era.

In the process of overhauling the roster, Jerry Dipoto & Co. filled the system with baseball rugrats, collecting youth of various skill and experience levels. One such rugrat—23-year-old right-handed pitcher Justin Dunn—is among five Mariners on FanGraphs’ latest top prospect list. Checking in at #89, one spot ahead of first baseman Evan White, Dunn helps move the Mariners’ rising minor league system toward relevance.

A three-year standout at Boston College, Dunn ditched the Mets’ blue and orange for a newly teal wardrobe when New York traded him and a carton of others to get Canó and Díaz. Burgeoning outfielder Jarred Kelenic (ranked as FanGraphs’ 84^th-best prospect) may represent the greatest haul in that mega-deal, but Dunn gives reasons for fans to salivate as well. With three to four above average pitches and 260 professional innings already under his belt, Dunn has the tools to eventually contribute at the major league level in a big way.

Dunn ended his 2018 ledger by striking out six or more hitters in eight of his final nine starts. In his last start at Class-A Advanced, the smooth-throwing pitcher fully demonstrated that he was ready for fiercer competition. Showing an impressive ability to repeat his mechanics and keep hitters off-balance, Dunn mixed his pitches beautifully en route to a seven-inning, 10 K, two-hit, no run masterpiece.

This triggered a bump to Double-A, the land where many lifelong studs get their first taste of adversity. Dunn was no different—his ERA bounced from 2.36 at A+ to 4.22 in AA—but he actually struck out more batters per nine innings than he ever had before. Even when he was pitching on the collegiate circuit, Dunn had never rung up 10.54 K/9 like he did for the Binghamton Rumble Ponies last year. This eye-popping strikeout rate surely caught the eyes of scouts and number crunchers, and absolutely piqued the interest of those in Seattle’s camp. Averaging just a tick under six innings per start, Dunn handled Double-A swingers with relative ease, and was hindered partly by an unreliable defense, as his ERA came in almost one run higher than his FIP.

Command may be the trait that holds him back. In looking at both the raw numbers and the 45/50 command ranking on FanGraphs, consistently locating his pitches has been the bugaboo of Dunn’s young career. Along with the aforementioned increase in K/9, the 6’2” righty battled a nasty case of the walks. 3.71 BB/9 and six wild pitches in 15 starts for the Rumble Ponies certainly draws some question marks but doesn’t seem like a reason to press the panic button. Given the already-flashy strikeout figures, Dunn stands to generate even more whiffs as soon as he wrangles in the wayward pitches that sometimes derail him. Even with the high amount of missed targets and balls to the backstop, Dunn brought home the Mets’ 2018 Sterling Award given to the organization’s brightest budding pitcher.

Similar to Justus Sheffield, the absolute worst-case scenario for Dunn is probably becoming a reliever. He possessed the talent to be both a first-round draft pick and a quick mover up the Mets’ ladder, but he also has a versatile track record dating back to college. Dunn’s junior year at Boston College featured ten relief appearances as well as two saves. He came out of the bullpen seven times in his early bird days as a Mets’ farmhand but hasn’t worked as a reliever since July 2017. Still, if need be, Dunn can tap into his reliever mindset and experience if that’s the direction Seattle sends him. Remember, Edwin Díaz also began his journey as a starter before transitioning into a closer, and the Mariners don’t really seem to have a clear candidate standing above his peers for the title of Closer of the Future.

Of course, the goal is for Dunn to use the next few seasons to mature into a bona fide, undeniable starting pitcher. The initial pitches in that progression will likely happen in Arkansas, with extra seasoning in Tacoma when the time is right. But should a shift to the later innings occur, whether because of neutralized attempts at being a starter, or simply because the team wants him in the pen, Justin Dunn is one of multiple top-100 pitching prospects that the Mariners can take their time with. That is not something we have been able to say for quite some time.