San Bernardino, California —— Entering play on Monday night, Arizona Diamondbacks right-handed pitching prospect Jon Duplantier is 9-1 with a 1.55 ERA over 17 games (16 starts) split between the Low-A Kane County Cougars and the High-A Visalia Rawhide, with 102 strikeouts over 93.0 innings pitched against just 63 hits and 26 walks. I observed the 23-year-old Rice University product in his July 21 start on the road against Inland Empire; below is Baseball Census‘ full Jon Duplantier scouting report, including video.
Jon Duplantier Scouting Report — Video
Our video of Arizona Diamondbacks right-handed pitching prospect Jon Duplantier shows his warm-up in the bullpen and mechanics in the game against the Inland Empire 66ers, where he allowed three runs on eight hits and three walks against seven strikeouts over 5.2 innings pitched:
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Jon Duplantier Scouting Report — Notes
Among the most polished pitchers I’ve seen in High-A this summer, Jon Duplantier has the use of four above-average pitches right now with very good life on all of them and an advanced understanding of how to sequence hitters. His fastball was 92-94 mph during Friday night’s start, and while the velocity is very good—and he can likely bump it even a bit higher when needed—it’s his very late, hard arm-side run that is most impressive. Duplantier stays on top of the pitch well, too, and the downward plane he gets when combined with that run make it a difficult pitch to square up, especially for right-handed hitters. His curveball, which sat 76-80 mph, flashed plus during his pre-game work with very tight spin and great 12-to-6 break, but he didn’t use it very much in game action on Friday and its command suffered in the times he did throw it. Nevertheless, it’s clear he has the arm strength and arm speed to throw the pitch well; it should continue to develop into a serious weapon for him just based on my rudimentary bullpen looks alone.
Duplantier also showed a slider on Friday night, and while it’s distinct from the curveball and gives him another breaking ball wrinkle in the mid-80s, he struggled with feel for that pitch. He gets great extension on it (as he does with all his stuff), but his command was imprecise with it and he was limited to using it ahead in the count when he could spot it down and away as a wipeout pitch to righties. Duplantier’s changeup at 80-82 mph is better than I expected, with great tumble and some arm-side run. The extension he gets especially helps sell his changeup, as it looks like a fastball out of his hand only to pull the string as it tumbles at the plate.
A tall, lean pitcher, Duplantier should grow into his body some more in the coming years, though he is 23 years old and may be near his final physical form. His arm action is long, especially in the back, and that could allow hitters (mostly lefties) to pick up his stuff very early. However, the benefit of that long arm action on the back end is the extension he gets out front at release; all of his stuff plays up because it jumps on hitters quickly and gives the appearance of him throwing even harder than he actually does. The Arizona Diamondbacks are relatively light on impact pitching talent throughout their system right now, and so Jon Duplantier should figure to be in the mix for a big league job relatively soon thanks to his maturity and polish with a deep repertoire.
Jon Duplantier Scouting Report — Projection
Duplantier has moved through the system relatively quickly, and the Arizona Diamondbacks no doubt have to be thinking about a big league debut for him by the end of next year if all goes right. Outcomes aside in that Friday night start (it was really the first one of the year where Duplantier was imprecise and got hit a bit for it), the righty is beyond the California League right now and should see some time in Double-A before this summer ends. From there, it’s likely he spends 2018 in the high minors before making his big league debut late next year (assuming good health and all the rest).
Long term, he has a deep repertoire and everything he throws shows great life, so as he further improves the consistency of his command he will only become tougher to hit. He understands how to sequence hitters, too and his ability to throw strikes with multiple pitches will only further accelerate his development path. I think he’s got a shot to be a mid-rotation (#3 starter) for the Arizona Diamondbacks by 2019, and if his off-speed command improves in time he could even out-shoot that projection by a good bit. In other words, Jon Duplantier ought to be a major impact on the club’s big league roster in the next eighteen months.
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