Prospect Report: Davidjohn Herz

High-upside lefthander is starting to incorporate three pitches with plus potential.

DJ Herz by Stephanie Lynn (@SRL590)

How acquired: MLB Draft 2019

Davidjohn (also goes by DJ) Herz came into the organization in the 8th round of the 2019 draft. The Cubs have placed an increased emphasis on higher upside selections in the draft. This strategy came with risks as the Cubs selected a bevy of players who would be described as raw and/or had a prior injury. Herz represented the former as clips available leading up the draft showcased projectability and a three-pitch mix that was was far more about “flashing” above-average pitches than repeating it on the mound. The Cubs identified Herz as an ideal pitcher to bring into the player development system with the upside as an impact pitcher who features a bulldog mentality on and off the mound.

For more backstory on DJ Herz, check out this article featuring an interview with DJ.

Mechanics and Control

Previously posted based on 2019 video: DJ Herz comes at the hitter with a lot of moving parts. It’s an athletic delivery, but one that is inconsistent. Herz uses a crossfire arm action that adds to deception to the hitter and eats up lefties. There is a very inconsistent foot strike (where his foot lands). In an ideal delivery, a pitcher will repeat his mechanics. Where a pitcher lands with their lead foot is vital to maintaining control, let a lone command. What Herz does succeed with is his ability to gather himself at the top of his windup. This offers hope that he can have more repeatable mechanics in the future, especially when factoring in that he was a three-sport athlete in high school.

2019 Mechanics

2021 Mechanics

2021: Herz’s delivery has come a long way since being drafted in 2019. It still has a lot of moving pieces to it, but it’s an athletic delivery. There are elements that he repeats well. Herz’s particular motion adds deception, which allows his low to mid 90s fastball with late life to play up. He gathers himself well and his hand break is consistent. In the follow-through Davidjohn will often fall off the mound to the third base side, but when he’s right he at least finishes in a balanced position. Despite long legs, one area for improvement is a longer stride to elicit better extension. Where Herz is still improving is his inconsistent foot strike. There are starts where it becomes apparent that he struggles with it. In recent starts, his mechanics are far more repeatable.


Herz has taken strides this year to improve his control and command. In multiple outings, it is obvious that Herz is in control over both his fastball and one off-speed pitch in-game. At times he is capable of commanding all three pitches in an outing, but that is an area of growth. At 19 in his first foray into professional ball, I’ll avoid capping Herz’s projected control and command. He has the tools to succeed with multiple pitches and at least average command in the future.

Pitching Arsenal

Fastball: Herz executes his fastball well. At the top of the zone, his four-seam fastball offers solid ride. He is able to elevate the heater as well as paint the outside corner when he is at his best. The fastball is sitting in the low-to-mid 90s at present, but in an interview with , Herz noted he believes there is more velocity to come. I have this as an average pitch right now, but it has significantly more upside in the future. When commanded well, Herz flashes plus with this fastball, especially as he’s successfully played elevated fastballs off his spike-curve and lower fastballs of his changeup.

“I was sitting 93-95 just in the bullpen in the lab. I’m hoping by [2021], I’m at 97-98.”

DJ Herz

Changeup: Herz has spent considerable time working to hone this pitch during the shutdown. His changeup is whiff inducing and able to both land in the strikezone and fall off the table generating feeble swings. The shape of this pitch varies, but at it’s best there is good depth and fade (into righties). This is an above-average pitch at its best.

Changeup for a strike
Changeup for the whiff

Curveball: I’ve already written about DJ Herz’s work with fellow Cubs pitching prospect, Chris Clarke to develop his new spike-curve. Herz’s effort to craft this pitch appears to have paid off well. Herz spoke this spring about how he was getting good bite on the curve, but having trouble to locate it. Those issues continued into his first start of the season. Since then, DJ has had considerable success utilizing the pitch as both an option in and outside the strikezone. His command of the curveball still wavers, but he has entire outings where he relies on the pitch. This spike-curve is a a heavy power offering with a 12-6 action. It already sits as above-average, but the curveball has plus potential.


Future Projection

DJ Herz is in the middle of a breakout performance this summer and a huge bright spot in an organization that has historically struggled to develop pitching. Herz was originally drafted with concerns about a future reliever profile, but with improved mechanics and the ability to showcase three pitches for strikes, he has largely quieted those concerns. As a 19-year-old in his first season of full season ball, there will be ups and downs with his performance this season, however with his deceptive delivery, bulldog mentality on the mound, and average (or better) command of three exciting pitches, DJ Herz boasts some of the highest upside in the entire Cubs system.