How recently claimed former top prospect can break out with the Pittsburgh Pirates

The Pittsburgh Pirates recently claimed southpaw Joey Wentz from the Detroit Tigers. Wentz was originally a first-round pick by the Atlanta Braves in 2016, but was dealt to the Tigers at the 2019 trade deadline for reliever Shane Greene. Despite once being ranked as the 45th best prospect in baseball by Baseball Prospectus, Wentz has yet to find his footing at the MLB level.

Wentz has pitched primarily as a reliever this year, working to a mediocre 5.37 ERA, 4.52 FIP, and 1.57 WHIP through 55.1 innings. Wentz has a respectable 23.6% strikeout rate, but he has given up walks at a 10.6% rate. While he has induced a roughly league average 88.8 MPH exit velocity and 42% ground ball rate, Wentz has struggled to limit the long ball with a 1.30 HR/9 rate.

It hasn’t been a good year for the former first-round pick, but Wentz is only 26 (turns 27 in October), and has shown some potential. He might be one pitch adjustment away from breaking out. But what exactly does Wentz need to do to reach that next level?

How can Pirates' new addition Joey Wentz break out?

First, let’s look at what Wentz already does well and how he could potentially build off of that. Wentz has some promising underlying numbers. His 4.23 xFIP is roughly league average and he has a SIERA below 4.00 at 3.97. Wentz’s cutter (37.3%), changeup (42%), and curveball (35.1%) have all induced a whiff rate over 35%. Each of these three pitches has an xwOBA below .300, with his curveball being the lowest (.240), and his cutter being the highest (.272). On top of that, none have induced a below-average exit velocity.

Wentz has three good pitches, all of which breed strong results, as well as induce a swings-and-misses at a high rate. He could prioritize one of these offerings as his primary offering. He already uses his cutter nearly as often as his four-seam fastball. Otherwise, Wentz could look to improve his worst offering, his four-seam fastball.

Opponents have a .341 BA, .518 slugging percentage, and .418 wOBA against Wentz’s four-seamer. Wentz hasn’t induced nearly as many swings and misses with it compared to his secondaries, with a 17.3% whiff rate. When opponents do make contact, they have barreled it up with a 91.4 MPH exit velo and 11.1% barrel rate.

But, through it all, his four-seamer does have some intriguing attributes. It sits at 93.8 MPH, which is about average, with above-average vertical drop (13.7 inches) and above-average horizontal movement (8.0 inches). Over the past year, Wentz has changed the way he throws his four-seamer after it ranked third to last in run value/100 pitches at -2.9. The change sacrificed some horizontal break, but added better ride through the zone. 

Despite the change in pitch movement, Wentz still throws the pitch more like he did last year than how he should be tossing it. Wentz only throws his four-seamer in the top edge of the strike zone 5.5% of the time. Between 2022 and 2023, Wentz used his fastball at the top edge of the zone more often, for comparison, at 8.8% of the time.

Wentz should be working further up in the zone and taking advantage of the impressive vertical movement his fastball now has. Take another lefty reliever, Andrew Nardi, as an example. His four-seamer has near-identical attributes (94 MPH, 13.9 inches of vertical drop, 8.3 inches of horizontal break), but opponents only have a .224 BA, .379 slugging, .307 wOBA, 89.4 MPH exit velo, and 8.3% barrel rate against it. Nardi works at the top edge of the zone with his four-seamer nearly 19% of the time (18.9%, to be specific).

Wentz figuring out his fastball could be the difference maker for him. He still uses it like the pitch he was throwing in 2022 and 2023 when it’s not the same sort of offering. His secondary stuff has already worked well this year and has consistently been solid in the past. If Wentz can make this change, he could be a nice waiver pick-up for the Pirates.