Arizona Diamondbacks Officially Release 2 Pitchers

The Arizona Diamondbacks have trimmed their Dominican Summer League roster, releasing right-hander Jhossua Castro from the DSL Arizona Black squad and left-hander Gregory Sanchez from the DSL Arizona Red.

The moves, logged on MiLB.com, mark the end of short organizational stints for two international free agents who never advanced beyond the entry-level circuit.

Castro, a 20-year-old from Bani, Dominican Republic, signed with Arizona on June 29, 2025.

Listed at 5-foot-11 and 165 pounds, the right-hander appeared in 21 games across two seasons and posted a 5-1 record with a 3.98 ERA, 25 strikeouts, and a 1.67 WHIP over 31.2 innings.

His 2025 debut showed promise with a 2.14 ERA in 21 innings, but command issues surfaced in 2026, when he allowed a 7.59 ERA and walked as many batters as he struck out in 10.2 frames.

The Diamondbacks shifted him between the Black and Red clubs several times during the summer before the release.

Sanchez, 21 and from San Francisco de Macoris, joined the organization on May 19, 2025.

The 5-foot-9, 170-pound left-hander worked in relief across 36 appearances, finishing 5-4 with a 7.46 ERA, three saves, 42 strikeouts, and a 2.17 WHIP in 44.2 innings.

His 2026 numbers reflected ongoing control problems: a 1-2 mark and 8.84 ERA in 19.1 innings. Like Castro, he bounced between the two DSL teams multiple times before Arizona cut ties.

Neither pitcher reached a domestic affiliate or cracked any meaningful prospect lists. Both remained confined to the Dominican Summer League, where clubs evaluate raw international talent with modest signing bonuses and limited long-term commitments.

Releases at this level are routine once seasons conclude, especially as organizations clear space for new international signings and evaluate which players warrant invitations to instructional leagues or further development.

The timing coincides with the broader free-agency window, during which Arizona has already seen higher-profile departures, including several major-league pitchers and position players electing free agency or being outrighted.

For Castro and Sanchez, the releases open the door to opportunities with other organizations or independent leagues, though their limited track records and elevated walk rates may limit interest.

In the larger picture, the moves underscore the high attrition rate for international pitchers signed as teenagers.

Most never reach the upper minors, and clubs treat DSL rosters as fluid developmental pools rather than long-term investments. Arizona’s decision simply formalizes that reality for two arms who spent their brief professional careers on the island.