Mariners claim RHP J.B. Bukauskas from Arizona

The Mariners made a roster move today, claiming righty J.B. Bukauskas off waivers from Arizona.

Bukauskas was originally drafted by the Houston Astros with the 15th overall pick in 2017 out of UNC, Houston’s first first-round selection of a college pitcher since Mark Appel. Bukauskas was a highly-regarded draft prospect at the time, with a mid-90s fastball and a plus slider, and projected to be a quick mover for the contending Astros, making top prospect lists the following spring. However, a heavy college workload led the Astros to slow-play him over his draft year, with just 10 “show me” innings at rookie ball and short season.

The Astros continued to develop Bukauskas as a starter, jumping him from short-season all the way to Double-A in 2018. Bukauskas finally got some stability in 2019, pitching 85 innings for the Corpus Christi Hooks, but while he continued to miss bats and strike hitters out, his walk rate crept up. The Astros packaged Bukauskas in the Zack Greinke deal, along with Seth Beer, Corbin Martin, and Josh Rojas, and leading this particular writer to breathe a sigh of relief at not having to look up how to spell “Bukauskas” multiple times a season.

After spending 2020 at the D-Backs alternate site, Bukauskas was slowed in 2021 by a right elbow flexor strain, only pitching 30 innings scattered between Triple-A Reno and Chase Field, all in relief. The injury bug bit again at the start of the 2022 season, with Bukauskas missing three months with a Grade 2 teres major muscle strain (the teres major is a muscle in the back, under the shoulder blade, that helps the long bone of the arm, the humerus, extend and rotate). Bukauskas never made it back to the majors in 2022, pitching just 20 innings for Triple-A Reno, although with some extremely strong numbers considering the bounce houses of the PCL: he cut down his walks to a career-low 5% while maintaining solid-if-unspectacular strikeout numbers (24%), and only allowed one home run. Nevertheless, Arizona didn’t see a place for him in their MLB-worst bullpen (-.7 fWAR, the lowest mark in the majors last season), and designated him for assignment this past week to make room for Zach Davies.

Health is obviously the biggest concern for Bukauskas; scouts have hated his high-effort delivery for years (the dreaded “inverted W”) and predicted a move to the bullpen, where his role now seems to be firmly entrenched. It will be interesting to see if the Mariners try to overhaul Bukauskas’s mechanics at all, or what piqued their curiosity about Bukauskas, who, on paper, maybe hasn’t always exhibited the kind of control the Mariners like in their pitchers. Part of that is he is heavily slider-dependent as his plus pitch—a whiff rate of 43% in 2021—and sliders are designed to end up out of the zone, so he needs to get bites on the slider or risk falling behind in counts. But when the slider is working, he can get righties chasing after it:

Or make lefties look downright silly. Here he is striking out everyone’s favorite trade target, Bryan Reynolds.

As for the fastball, the shorter (generously listed at six foot even) Bukauskas has tended to work at the bottom of the zone, which creates deception along with the slider but can also be a trickier pitch location to land for strikes.

Looks from his time in Triple-A are limited, but it seems like he might have gone to throwing the fastball higher in the zone to create weak contact, such as this:

Bukauskas still has a minor-league option remaining, allowing the Mariners some flexibility in how they might use him over the upcoming season, and making the D-Backs’ decision to DFA him even more puzzling. Also puzzling: J.B. Bukauskas’s name is Jacob Allen. Where does the B come from, J.B.? At any rate, I suppose I’ll have to put some effort into learning how to spell his name correctly on the first try instead of doing what I’ve done in the past, which is just typing Bs and Ks and Ss with some vowels sprinkled in (Babadooksas).

As the 40-man was full, the Mariners made space for Bukauskas by designating Alberto Rodríguez, who Nick literally just wrote about for the 40 in 40, for assignment. We’ll still publish it because we are completionists here at LL, but consider this the 40 in 40 for J.B. Bukauskas. Rodríguez, acquired in the Taijuan Walker trade, took a big step backwards last season, both on the field and in his conditioning, and Kyle Glaser of Baseball America suggested in a recent chat that the team wasn’t pleased with his conditioning. The Mariners are betting that no other team will scoop up Rodríguez after his stepback season, but it’s not a strong vote of confidence in the progress of the young outfielder.