Shawn Trewartha | July 9, 2026

While the 2026 Rockies are clawing and scrapping to improve on their 2025 campaign, there have been some encouraging signs at the plate. At the halfway point of the season, the Rockies’ hitters sport a middle-of-the-pack OPS+ (95) and home run total (94). They also rank fifth in MLB with a .254 batting average. It’s the pitching staff that has carried the lion’s share of the struggles.

The bullpen (or the “arm barn,” as they’re rightfully known around here) has been especially underwhelming. What was expected to be the strength of this team has instead been its biggest disappointment. After an encouraging showing from the young arms in 2025 that continued through the first few weeks of this season, the bullpen’s performance has collapsed, contributing heavily to MLB’s worst 5.58 ERA.

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Not many bullpen arms burst out of the gate early, with the obvious exception of Antonio Senzatella. Regardless of where they started, however, nearly every pitcher saw his production decline when comparing March/April to May/June.

Juan Mejia provides a good example. Through March & April, he posted a 3.03 FIP despite a 5.02 ERA, while striking out 10.0 batters per nine innings and walking just 3.1. Since then, over May & June, his walk rate has ballooned to 7.6 per nine. At the same time, his FIP has climbed to 4.17 and his ERA has soared to 7.13.

Victor Vodnik experienced similar issues with a rising walk rate. His walks per nine innings increased from 5.0 to 10.3. Interestingly, despite his walk rate more than doubling, both his ERA and FIP decreased slightly when comparing March & April to May & June.

Brennan Bernardino and Zach Agnos both saw significant increases in their FIP and ERA. While each pitcher’s walk rate also increased, the larger factor behind their decline appears to be a sharp drop in strikeouts. Bernardino’s strikeouts per nine innings fell from 7.8 to 5.9, while Agnos’ dropped from 8.3 to 5.1.

Jaden Hill is the confounding case out of the bullpen. The hard-throwing right-hander has seen his ERA climb from 3.18 in March & April to 6.43 in May & June. However, his strikeout rate has remained nearly identical, while his walks per nine innings have actually improved from 6.5 to 5.8. His hard-hit rate also dropped from 50% to 28%, and even his BABIP improved over the same stretch.

It turns out Hill has simply been a bit unlucky over the last two months. Both his batting average against and slugging percentage against have exceeded their expected values. His FIP, a fielding-independent metric often used in place of ERA to evaluate a pitcher’s performance, also improved from 4.24 to 4.03.

While Hill has not been spectacular this season, he has clearly pitched slightly better than his traditional numbers suggest. Unfortunately, that’s sometimes the reality of pitching at Coors Field.

Juan Mejia

I want to highlight Juan Mejia specifically because I believe he will be a key member of this arm barn moving forward. He could fit in nicely as a regular setup man or even a closer next season when the Rockies are hopefully more competitive, and bullpen roles are defined by performance rather than necessity.

In 2025, Mejia emerged as one of the best relief pitchers in baseball. He relied on a two-pitch mix consisting of a fastball and a sweeper to hold opponents to a .199 expected batting average, ranking in the 92nd percentile across the league. He consistently generated weak contact while maintaining an excellent 26% strikeout rate.

He has not been nearly as dominant in 2026, particularly over the last two months. During March & April, Mejia generated a 22.5% whiff rate on his fastball and a 46.9% whiff rate on his sweeper. Those figures have fallen to 20.5% and 40.0%, respectively. The regression of his sweeper is especially concerning when comparing his expected slugging against by pitch. Opponents’ expected slugging against the pitch has jumped from .170 in March & April to .391 in May & June.

Now, it’s likely Mejia has been working closely with the new pitching staff to make adjustments throughout the season, and those changes can come with some growing pains. One notable adjustment has been to his mechanics: on his sweeper, his release point has moved more than four inches closer to his body.

Pitching Mechanics

He has also adjusted the rotational axis of his sweeper, increasing the angle by roughly 10 degrees. The apparent goal seems to have been trading some vertical movement for additional glove-side break. The adjustment has also come with a slight decrease in spin rate. In practice, however, the changes have not produced the desired results. During May & June, Mejia’s sweeper averaged nearly three inches less induced horizontal break, making it far more desirable for a hitter. 

Movement Profile

Pitch Location

As shown in the pitch location figure, Mejia’s sweeper was not located well during May & June. Earlier in the season, when the pitch was generating a much higher whiff rate, its average location was on the outside black to right-handed hitters. By May & June, that average location had drifted toward the heart of the plate, helping explain both the surge in slugging against the pitch and the decline in its whiff rate.

Pitch Mix

Beyond his mechanics, Mejia has also been adjusting his pitch arsenal to align with the organization’s desire for pitchers to feature a deeper mix of offerings. He has introduced a sinker, throwing it roughly 8% of the time, almost exclusively to right-handed hitters. The sample size remains small, but the early results suggest it could become a nice complement to his sweeper moving forward.

A fourth pitch is something Mejia has experimented with throughout the season, but nothing has stuck. He opened the year throwing a slider before replacing it with a changeup, though both remain very much works in progress.

The Rockies’ bullpen has underperformed expectations in 2026, but Mejia’s season, along with others, should not be viewed as a lost year. Pitch development is rarely linear, and the changes he has made show a pitcher actively searching for ways to improve. The challenge now is turning those adjustments into execution. If they can do that, the Rockies may already have one of their most important bullpen pieces not just for 2026, but for the next competitive window.

Written by Shawn Trewartha.