Peguero joins a pool of hard-throwing relievers who will compete for a spot in Milwaukee’s bullpen. At the time of the trade, General Manager Matt Arnold named Junk as a candidate for the starting rotation. However, the 27-year-old has just 24 2⁄3 big-league innings to his name, and the subsequent signing of Wade Miley complicates his path to starts.
Despite his limited track record and standing on the depth chart, Junk is an under-the-radar candidate to carve out a productive role with the Brewers, whether as a starter, reliever, or in a hybrid role.
A 22nd-round draft pick of the New York Yankees in 2017, Junk has never been a premium prospect. Still, FanGraphs rated him as the Angels’ seventh-best prospect after the 2021 season and 17th in the Brewers’ system after the trade.
Junk features an intriguing arsenal headlined by a four-seam fastball, slider, and curveball. He also keeps a fringe changeup in his back pocket. Junk has yet to recognize how his stuff plays and the best way to utilize it, which has been his greatest roadblock to success.
Some of that may be due to his surroundings. The Angels have failed to build playoff teams around perpetual MVP candidate Mike Trout due to poor player development. Junk is now moving to a Brewers organization that has invested heavily in that area, including a $60 million renovation to the club’s Arizona complex that was completed ahead of the 2019 season.
The renovation featured a high-tech pitching lab that instantly provides pitchers and coaches with instant feedback on arsenals and mechanics in the form of in-depth data. The Brewers have since forged a reputation as one of baseball’s leading organizations in the realm of pitching development. Junk is in a position to discover his identity as a pitcher, which is the key to a breakout.
Junk’s four-seam fastball has roughly average velocity and is straight as an arrow. Per Baseball Savant, it averaged 92.5 mph and just 1.6 inches of horizontal movement last season. However, it’s also a high-spin pitch that ranked in the 83rd percentile in spin rate.
That spin gives Junk’s fastball a rising effect as it approaches the plate, meaning it plays best at the top of the strike zone. Freddy Peralta’s fastball, which induces whiffs at an elite rate in the upper third of the zone, is a good comparison.
The swing-and-miss potential of Junk’s fastball has not surfaced in his limited MLB exposure (16.5% whiff rate), but it’s there. The pitch proved adept at generating empty swings from Triple-A hitters last season when elevated, including an elite whiff rate when opponents chased above the zone.
Junk’s fastball is most challenging to make contact with when he elevates it to his arm side. The problem is that he throws a steady diet of belt-high four-seamers over the outer third of the plate and knee-high down the middle.
Both of these locations diminish the deceptive qualities of Junk’s fastball. While an outer-third pitch is tougher to pull and can limit extra-base hits, it gives the hitter additional reaction time, thus making it easier to make contact. When thrown at the knees, Junk’s rising fastball runs directly into barrels instead of avoiding them, yielding a 103.1 mph average exit velocity on 16 batted balls.
Compare Junk’s fastball location to Peralta, who consistently pounds opponents up and in.
Junk’s fastball can be effective when properly utilized. Optimizing his four-seam location will be instrumental in turning him into an effective pitcher.
Many scouts cite Junk’s slider as his best secondary pitch, but he has been seemingly unable to settle on a shape for it. Here’s a sweeping breaking ball from his September 2021 cup of coffee with the Angels.
Janson Junk, Nasty 82mph Slider. pic.twitter.com/FvR1cXrq9n— Rob Friedman (@PitchingNinja) September 30, 2021
That looks like a strong slider, and the numbers back it up. It averaged 15.6 inches of horizontal movement, 6.7 inches more than the average slider thrown at a similar velocity and released at a similar distance from home plate.
Junk experimented with a dramatically different slider throughout the 2022 season. This slider was harder with later break and stricter horizontal movement than the previous iteration.
Junk eliminated a significant amount of break on his slider, both vertical and horizontal. He also sacrificed nearly 300 rpm of spin on the pitch. At first glance, it seems he intentionally made his slider worse. A likely explanation is that the Angels sought greater separation between his slider and 12-6 curveball and preferred less break late to more break early. Perhaps they were aiming for more of a cutter/slider hybrid than the slurve-like pitch that Junk previously threw.
Brooks Baseball utilizes the PITCHf/x tracking system. It includes spin-based vertical movement measurements isolated from the effects of gravity and features minor-league data from 2022. As such, it paints a more detailed picture of how Junk’s slider changed throughout the year.
Junk’s slider averaged -0.61 inches of vertical movement during the season’s first month, meaning it dropped less than his 2021 slider, which averaged -1.11 inches in his big-league debut. As the year progressed, Junk continued to lose vertical break on his slider, a trend that peaked in July. He regained some of that drop over the season’s final two months.
There are a number of explanations for the inconsistency. Perhaps Junk was trying to reshape his slider during the middle of the season, lacked consistency with his release, or has multiple versions of his slider that pitch tracking systems do not clearly distinguish. It may be a combination of all three. In any case, there is circumstantial evidence that Junk is still working to figure out the best version of his slider.
In addition to experimenting with its shape, Junk has yet to find how the slider best fits in his pitch mix. As the season progressed, he leaned heavily on it to the point that it became his primary pitch during the second half.
Whether this is the best way for Junk to allocate his pitch usage is debatable. Both his fastball and curveball ceded time to the slider in the second half, but he could generate more whiffs by pairing high fastballs with curveballs more frequently.
Junk’s 2022 season points to a pitcher who is continuously tweaking his arsenal or, at the very least, struggling to use it properly. A move to an organization that has excelled at pitching development in recent years could provide him with the answers he needs. By optimizing his fastball location, settling on a shape for his slider and refining his pitch mix, Junk can take a step forward and establish himself at the game’s highest level.