The Diamondbacks selected Jon Duplantier (pronounced doo-PLON-tee-AY) in the third round of the 2016 draft out of Rice University. The six-foot-four, 240 pound righty was the starting pitcher in the 2018 Fall Stars game in the Arizona Fall League and pitched well during his fall league stint, striking out 32 hitters in just under 21 innings over six starts.
Duplantier has been one of the top statistical performers in the recent history of the minor leagues, and owns a career 1.79 ERA over 211 innings in three seasons in the Diamondbacks organization. In 2017 he posted a sparkling 1.39 ERA in 24 starts split between Kane County and Visalia, which was the second lowest number in the last 25 years, only bested by Justin Verlander in 2005.
He’s battled some injuries while at Rice, and has suffered a few setbacks in pro ball also. In fact, a shoulder impingement while at Rice caused a complete delivery overhaul. He missed most of 2016 after getting drafted due to elbow soreness, and in 2018 a hamstring injury and then bicep tendonitis limited him to 67 innings.
He has a bit of deception with the delivery. He starts with a quick step back but then slows down due to his long arm action which gives the hitter a look at the ball behind him before he slings it to the plate. His low 3/4 arm slot makes him tough on righties, and he should settle in just around a strikeout per inning with a heavy groundball tilt. He’s posted groundball rates up over 50% in each of his stops in the minors, and profiles as a number three starter long term. The injury history is a tad worrisome, but he’s a good bet to reach his ceiling if he stays healthy.
The Rankings
Duplantier ranks 71st on our team Top 100. Matt Thompson ranked Duplantier third in his Arizona Diamondbacks top 30.
The Tools
Fastball (60 Present/60 Future): Duplantier pounds the bottom tier of the strike zone with his heavy 92-94 sinking fastball. There are a few variations to this pitch, and it gets tremendous sink and run. It’s a heavy pitch and is the main driver behind his 53% groundball rate in 2018. He can also get a tremendous amount of run away from left-handed hitters as a different look.
Slider (55 Present/60 Future): Duplantier’s slider is his best secondary offering, and the only one that gets a plus grade. His low 3/4 arm action helps this pitch play up, and it sweeps across the zone. He works the slider primarily low in the zone and extends the plate away from righties. It’s an uncomfortable pitch for right -handed hitters generating feeble hacks.
Change (45 Present/55 Future): Duplantier uses this pitch primarily against lefties as a different look. It needs some refinement as it can be too firm at times. There isn't much horizontal movement but the bottom just falls out of this pitch. Another pitch that generates ground balls at a high clip.
Curveball (45 Present/45 Future): This is a show me pitch for Duplantier, and one he has struggled to get on top of at times due to his low-3/4 arm slot. The primary purpose of this pitch is to steal a strike and give the hitter another pitch to think about.
Conclusion: This call-up appears to only be for the short term, as the Diamondbacks pitching staff needed a fresh arm after a rough opening series with the Dodgers that saw them allow 42 runs over four games. Duplantier is expected to pitch out of the bullpen while he is with the big club, but should be the first option called upon if they Diamondbacks need a starter in 2019. He’s a number three starter long term for me, and can show flashes as a bit more than that when the sinker is really moving.