Carmen Mlodzinski is one of the more intriguing arms on the Pirates’ staff, and not just because it looks impossible to pronounce on paper (its “muh-GIN-skee”). After spending two seasons working primarily in low-leverage relief, the Pirates gave him an opportunity to open the 2025 season in the rotation. The experiment produced mixed results. Mlodzinski often handled hitters the first time through the order, but he rarely worked deep into games and reached six innings only once in his first nine starts. By mid-May, he was optioned to Triple-A and soon returned to a familiar multi-inning relief role.
What followed was not simply a return to form, but a stretch that hinted at a more complete version of the right-hander. Over the remainder of the season, he logged significant bulk innings out of the bullpen and posted strong run-prevention numbers across 99 total innings, finishing with a 3.55 ERA and 3.33 FIP. His strikeout rate remained modest, but he paired it with a career-low 6.4% walk rate and allowed only eight home runs all year.
One of the most meaningful changes from 2024 into the second half of 2025 involved his arm angle and how it translated to his breaking ball command. Previously, there had been a wider separation between the release of his fastball and slider, which contributed to inconsistent location and too many noncompetitive pitches below the zone. By tightening that gap and raising the slider’s arm angle, he was able to keep the pitch on the edges more frequently. The overall difference in edge-of-zone rate was only a few percentage points, but it materially affected his outcomes, helping drive the sharp reduction in walks and forcing hitters to engage earlier in counts.
Mlodzinski’s evolution also showed up in how he shaped his repertoire. Earlier in his career he leaned on a four-seam fastball, a changeup, and a pair of lateral breaking pitches. As he prepared to start in 2025, he experimented with a sinker and splitter in an effort to build a deeper mix capable of turning over a lineup. The transition was uneven at first, particularly because his slider and sweeper were often left in hittable locations. Midseason, however, he introduced a curveball that gave him something his arsenal had largely lacked: a true vertical offering. While not overpowering in isolation, the pitch created a different visual plane for hitters and complemented his fastball shapes by allowing him to work both north-south and east-west. As the season progressed, that curveball took on a larger role, while the earlier breaking-ball mix was scaled back.
The results were evident in his performance down the stretch. Used frequently for multiple innings at a time, Mlodzinski provided stability in a hybrid role that bridged the gap between the rotation and the late-inning bullpen. He demonstrated the ability to carry his stuff beyond a single frame, an important marker for any pitcher the Pirates might again consider as a starter.
Now, entering 2026, Pittsburgh appears ready to give him another opportunity to compete for a rotation spot. The skepticism that accompanies that decision is understandable given how the first attempt unfolded, but it risks overlooking how different the pitcher looked by season’s end. Mlodzinski showed improved strike throwing, a more coherent pitch mix, and an ability to manage contact without relying solely on swing-and-miss. Those traits give him multiple paths to value, whether as a back-end starter capable of working efficiently through lineups or as a flexible, high-leverage option who can absorb significant innings.
Projection systems have taken notice, forecasting one of the lower ERAs on the staff behind only the club’s most established arms. For a pitcher who entered professional baseball with a relatively limited collegiate track record due to injury and the pandemic-shortened 2020 season, his development has been less linear than iterative, with each year bringing adjustments to usage, repertoire, or approach.
The Pirates may still be determining the best role for Carmen Mlodzinski, but the second half of 2025 suggested that the question is no longer whether he can contribute meaningfully at the major league level. The more relevant issue is how to deploy a pitcher whose evolving arsenal now gives him the versatility to impact games in several different ways.
