Jon Duplantier: Starter or Reliever?

Jon Duplantier was a 3rd round draft pick out of Rice University in the 2016 draft. The big right hander (6’4”, 225 lbs) showed a lot of upside with a mid 90’s fastball and good changeup and curve. HERE is a good scouting report heading into the 2016 draft. However he missed all of 2015 with a shoulder impingement. From that report linked:

There’s little question about Duplantier’s ability: he could develop into an above-average starter or a power closer. The main doubt is health: Rice pitchers have a reputation as ticking time bombs when it comes to injuries, and Duplantier has already missed a year with shoulder trouble.

Indeed, he pitched only 1 inning for the Dbacks Hillsboro affiliate after the draft, and was shut down immediately with elbow soreness. However he rebounded with a dominant season in 2017, making 24 starts, and throwing 136 innings and posting a 1.39 ERA across two levels, A, and Advanced A. He was nearly unhittable, allowing just 6 Hits per 9 and 0.4 HR/9, while Striking out 11 per 9.

This rocketed him up to the top of the Organization’s prospect rankings, and he started off well after being promoted to AA in 2018. In his first 7 starts he had a 2.52 ERA and a 40/11 K/BB ration in 35 IP. But the injury bug struck again, as he was shut down for two months with biceps tendonitis. He returned to finish out his season well, but only pitched 74 innings in 16 starts total, so was sent to the 2018 Arizona Fall League to get in some more work. He did well there, and I mostly liked what I saw, which you can review in game reports HERE and HERE. This was my summary:

This is the 4th time I’ve seen JD pitch now, and I feel like he is already able to get major league outs. His fastball is usually around 95, ranging 93-96, and he has had trouble spotting it the last few times I’ve seen him. Even when he does, hitters can make contact on it and hit it pretty hard. It’s his breaking pitches that set him apart. They are sharp, and he has been throwing them over or around the plate, inducing a lot of swing and miss from them. With a little better fastball command to set up his breaking pitches, JD is capable of dominating.

Duplantier did not make the 2019 rotation out of spring training, but thanks to the pitching staff and bullpen getting shellacked in the opening series in LA, the team immediately needed an arm, and they called up Duplantier on April 1st. It could not have gone any better. He relieved Merrill Kelly with the team holding a 9-3 lead, and proceeded to throw three scoreless innings, allowing just 1 hit, striking out 2, and not walking a batter. A pretty cool foot note to that game was that Kelly (win) and Duplantier (save) became the first duo to earn the victory and pick up a save while making their Major League debuts in the same game.

He made one more relief appearance on April 7th and then was optioned down to Reno ostensibly to begin building his workload as a starting pitcher. It didn’t quite work out that way though. He made three short starts for Reno, never getting past the 3rd inning, before being recalled again on April 28th. He threw 4 more scoreless innings against the Cubs, and then was sent down again. He made an aborted start for Reno on May 4th, and failed to get out of the 1st inning, walking three batters. He was recalled to reliever again, and then sent down again. This pattern repeated itself throughout the season. In all he was called up 6 separate times. He did make 3 starts for the DBacks in one of those callups.

He once again encountered the injury bug, and had to be shut down for one month due to a sore shoulder. Perhaps it was due to being called up and sent down so much, or shuttling between starting and relieving, but as the season wore on his command got worse and his velocity dipped. The sharpness to his breaking stuff wasn’t really there, and he kept falling behind in counts and then started to get hit hard when he came into the zone with his fastball.

You can see clearly in the graph below, the velocity he showed in the fall league in October 2018 and in spring training 2019, subsequently waned soon after being recalled multiple times, and then dipped all the way down to about 91-92 by the second half of the season. You can also see full table with game by game velo numbers HERE

In all, Duplantier only threw 80 innings in 31 games, 17 starts Majors/Minors combined. He never threw more than 5 innings in any outing, and he did that only twice.

It’s easy, even tempting to point to the multiple call ups and demotions and flipping back and forth between starting and relieving as the primary cause of his inconsistency, shoulder soreness, and drop in velocity. It certainly was a very strange way to handle a pitcher with both his in jury history and his pedigree. It seemed like the team was torn between wanting to continue his development as a starter, and utilizing a good arm in the midst of a wild card drive.

Coming into spring training 2020 he was probably 6^th or 7^th on the rotation depth chart. Once Spring training was shut down and Mike Leake opted out he might have had a chance to crack the rotation when things finally started up in July. But he got injured once again. Actually shortly after shutdown while working out on his own he suffered a forearm strain. The imaging was clean, but he was in pain and had to be shut down and receive treatments. When things started up in June he was rehabbing with the team but not on the 60 man player pool, and after a bullpen felt pain in his elbow and was shut down again. Finally, when he got going again in mid September he was pain free and it hasn’t bothered him since.

Not done with trials and tribulations, during spring training 2021 he suffered a freak injury, cutting his right index finger while shaving. It was incredibly frustrating, but he has dealt with it and all the adversity with determination to keep going. He finally made it back to the majors last week, losing to the Cardinals after going 4 ²⁄₃ and giving up 4 runs on 7 hits, 2 walks and a homer. He struck out 5. He probably pitched a little better than his line showed, but the 94 MPH fastball still wasn’t anywhere to be seen, averaging 91.8

Dup gave a 12 minute ZOOM interview the next day. He covered a lot of ground , talking about overcoming all the injuries, his drive and determination. He really is an impressive young man and you can sense his intelligence. I asked him a rather pointed question: While I acknowledged he’s a team player, I wanted to know how important it is that the team commit to him as a starting pitcher at this point.

“Ooh. That’s the heavy hitter, huh ? ummm... (long silence) It’s not so much if the team commits to me as starter. Obviously I’ve grown up my baseball life as a starter. I was drafted as a starter, and I came up through the minor leagues as a starter. I’m partial to starting. Like you said, I’m a team first person, I try to be a team first person. Obviously there’s some stuff... there’s a lot of... I mean rightfully so , we’re humans and this is a team sport with a lot of individual statistics tacked to it. So I would love to start. But being teams first....that’s my directive....it’s just my default. So how important is it that they commit to me as a starter ? (another pause) . I just want to help the team win. So I would like to be committed to trying to help the team win as a starter or a reliever I just want to do something and do something well.“

Full Duplantier audio [or link]

Following up with Torey yesterday, I challenged him a bit regarding how the team has handled Dup and whether they would commit to him as a starter.

Well, first of all I think we think very highly of Jon and we’ve just gotta be mindful some of the things we’ve been asking him to do in the past have been a challenge to him. We’re aware of that. We strive to treat our athletes as fairly as possible. I think we try to be as firm and fair and as consistent as we can be. I think Jon will get some opportunities to get the baseball and start and show us what he can do.

He’s starting against Milwaukee tomorrow. If he can stay healthy I think it’s time to give him 12 uninterrupted starts and see if he can make it. Any pitcher can have a bad month, so 5 starts isn’t going to satisfy my own curiosity. But at least with a dozen starts they’ll know. Will it work ? I don’t know. But this is exactly the kind of season you can answer these types of questions. If he can’t hack it, you either transition him to the bullpen or trade him. I personally am rooting for him to make it as a starter.