Zach Peek: Behind the Curtain of Another Rule 5 Selection by the Brewers

While the Brewers did lose one pitcher they would have liked to hold onto in Wednesday's Rule 5 Draft (Shane Smith, taken first overall by the White Sox), they also added two new arms over the course of the day. Connor Thomas joined the fold in the MLB portion of the draft, but there was another selection in the minor-league portion who is worthy of a deeper dive.

Zach Peek, selected out of the Orioles system, was a sixth-round selection by the Los Angeles Angels in 2019 out of Winthrop. In December of that year, the right-handed pitcher was dealt to Baltimore as part of a trade that sent Dylan Bundy to the Angels. Due to COVID, he didn’t make his professional debut until 2021.

In that first season, Peek posted a 3.80 ERA across Low-A and High-A, striking out 120 batters in 90 innings along the way. He got off to a strong start in Double-A in 2022, as evidenced by his 3.57 ERA and 3.50 FIP through 11 starts. Unfortunately, that season was cut short by an elbow injury that required Tommy John surgery. 

Peek returned to the mound in the last few weeks of the 2023 season. He was injured once again in early 2024, though, this time with a shoulder issue. Including eight innings in the Arizona Fall League in 2023, Peek has only pitched a total of 33 ⅔ innings since mid-2022.

When he has been healthy, Peek’s numbers have always been above-average, even if they don't jump off of the page. This is a viable mode of acquiring future big-leaguers, too. Oliver Dunn was selected in the minor-league portion of the Rule 5 by the Phillies in December 2022, under similar circumstances, Both Peek and Dunn had battled a number of injuries, but showed signs of big-league ability whenever they were healthy. 

Despite his advanced age, Peek's development has been limited the last couple of seasons, meaning there might be some room for growth left in the tank—more than you might expect from your average 26-year-old pitcher, at the very least. That, along with his pitch mix, is one of the main reasons this pick might end up being more noteworthy than it would appear at first glance.

It’s important to note that the above graphic is gathered from a very small sample, shortly after returning from Tommy John surgery, and includes only 20 total pitches from his lone AFL outing on a Statcast field. However, it does help give us a peek (pun very much intended) at what he brings to the table, in terms of his repertoire. 

His four-seam fastball has an average shape coming from his release height. It should be able to miss some bats at the top of the zone, but generally appears to be pretty hittable if it is left in the lower two-thirds. Velocity-wise, it has largely been a low-90’s offering, though he has reached back for 95 in the past and it sounds like he may have a bit more in the tank since his full return from Tommy John. 

Despite the four-seamer's relative normalcy, Peek’s overall fastball profile is one that the Brewers have been able to maximize numerous times in recent years. He throws both a two-seamer and a cutter, to go along with that four-seam. Based on this small sample, the cutter looks like a pitch the Brewers may have him throw more often, as it grades out a bit better than average.

The curveball is a high-spin offering, with over four inches more induced drop than the average curveball thrown around 77 MPH, to go along with average sweep. It’s a pitch that he showed good feel for being able to land for strikes early in his career, and he seemed to rediscover that in 2024 in his small sample, it's long been considered his best pitch by scouts.

Peek only threw one changeup in his AFL outing. It was (noticeably) around 10 MPH slower than his average fastball, and he did a decent job of killing the spin on it. Velocity differential, along with good command, can make up for some movement shortcomings on a changeup. However, visually, the changeup appears to have a bit more depth than the numbers on that one pitch sample would indicate. 

While his one-inning sample in the AFL didn’t include any sliders, he appeared to throw one of those, as well. It seems to have the shape of a shorter slider, likely on a similar plane to his cutter, but a bit slower and with more glove-side movement. It has the appearance of a pitch that he could use as a putaway offering against right-handed hitters.

One of Peek’s few outings in 2024 was his very last one, which was a rehab assignment against the Brewers' Low-A affiliate, the Carolina Mudcats. He threw two innings in relief in that outing, allowing two hits and one earned run. He also struck out four Mudcats and walked zero. In the video below, you can see his full repertoire on display (admittedly, not from the greatest camera angle), with a number of the pitches being thrown against some of the Brewers top prospects: Braylon Payne, Juan Baez and Eric Bitonti.

Peek has a six-pitch mix, all of which at least show signs of being usable MLB offerings. Though he was older, he was still moving relatively quickly through the Orioles system before battling through those two major injuries. Since returning from the second of them, there are some signs of his stuff taking a step forward, too.

Every MiLB Rule 5 selection will have holes in their profile, but Peek’s seem to be mainly tied to his age and injury history. There were some walk issues coming off of Tommy John, but that's not uncommon. As mentioned earlier, Oliver Dunn was a MiLB Rule 5 selection in 2022, but so was Isaac Collins, who made his MLB debut with the Brewers last year. With the amount of talent in some organizations, good players can fall through the cracks and wind up available in this portion of the draft.

Peek has the type of profile that, with some tinkering from a Brewers development staff that seems to specialize in working with his type of pitch mix and some better fortune on the injury front, could be capable of getting outs at the MLB level. He seems like a candidate to begin the campaign in Double-A with Biloxi, but it would not be too surprising to see him get his first opportunity in Triple-A to start 2025. 

Interested in learning more about the Milwaukee Brewers' top prospects? Check out our comprehensive top prospects list that includes up-to-date stats, articles and videos about every prospect, scouting reports, and more!