The Arizona Fall League begins next week and the Phillies have eight players on the roster of the Surprise Saguaros. Between now and the AFL Opening Day, we’ll take a look at each of those players. Next up is right-hander Eiberson Castellano.

Castellano is a 6-foot-3, 160-pound pitcher from Maracaibo, Venezuela. The Phillies signed him in July 2018 for just $10,000 as an international free agent. Castellano began his professional career in 2021 in the Dominican Summer League, as his development was delayed by the pandemic and organizational depth.

Minor League Career Progression

Castellano’s minor league journey has been steady but unconventional. He debuted with a dominant 1.09 ERA over 33 innings in the DSL in 2021, showing early promise. In 2022 and 2023, he pitched for the Clearwater Threshers in the Florida State League, posting a pair of inconsistent ERAs of 3.51 and 5.04 respectively. His 2024 season marked a turning point though, as he transitioned from the bullpen to the rotation, splitting time between High-A Jersey Shore and Double-A Reading. Over 103.2 innings, he struck out 136 batters with a 3.99 ERA and a WHIP of 1.14. In 2025, his performance regressed slightly, with a combined 6.44 ERA at the same two levels, though he still maintained a respectable strikeout rate.

Pitch Repertoire and Effectiveness

Castellano throws a three-pitch mix: a fastball, curveball, and changeup. His fastball averages just over 94 mph and can touch 98, delivered with good extension and late life. It’s not overpowering in terms of velocity, but it plays up due to his improved command. His curveball, thrown at 80–82 mph, is his most effective weapon, generating a 49 percent whiff rate in 2024 thanks to its power and depth. The changeup sits in the mid-80s and features sink and fade, producing a 39 percent miss rate. He mixes all three pitches well, with usage leaning slightly toward the curveball and changeup in high-leverage counts. His pitch sequencing has improved, contributing to a 31 percent overall miss rate in 2024.

Sabermetric Profile

From a sabermetric standpoint, Castellano’s strengths lie in his strikeout ability and improving control. His career minor league K/9 sits at 10.8, with a BB/9 of 3.5 and a strikeout-to-walk ratio of 3.06. His WHIP across all levels is 1.26, and his FIP indicators suggest he’s slightly better than his ERA would imply, especially in 2024 when his xFIP was notably lower than his actual ERA. His ERA- and FIP- metrics, adjusted for league and park, place him slightly below average in 2025, but his swing-and-miss stuff remains promising. He’s shown vulnerability to hard contact when behind in counts, and his pull percentage against suggests hitters can sit on his fastball if his secondary pitches aren’t landing.

Injury History and Impact

Castellano was placed on the 7-day injured list in mid-2025 with an undisclosed issue but was activated by late July. While the nature of the injury wasn’t publicly detailed, his performance post-IL stint showed some inconsistency, possibly linked to lingering effects. There’s no record of major arm injuries or surgeries, which is encouraging for his long-term durability. However, the brief IL stint and subsequent dip in command suggest that even minor setbacks can affect his rhythm and development.

Rule 5 Draft and Organizational Status

In December 2024, Castellano was selected by the Minnesota Twins in the Rule 5 Draft, a sign that other organizations saw upside in his swing-and-miss profile. However, he was returned to the Phillies in March 2025, indicating he wasn’t quite ready to stick on a major league roster. He remains a depth arm in the Phillies system, ranked 24th in their pipeline, with a projected ETA of 2026 depending on health and consistency.

Projection and Development Outlook

Castellano’s future hinges on refining his command and maintaining the effectiveness of his curveball and changeup. If he can consistently throw strikes and avoid walks, he profiles as a potential middle reliever or back-end starter with swing-and-miss upside. His lean frame and late development suggest there’s room for physical growth, which could add velocity or durability. Continued success at the Double-A level and a clean bill of health will be key to his advancement.