Luis Caballero Named 2026 Manager of Inland Empire 66ers

Luis Caballero will manage the Inland Empire 66ers for the 2026 season, the Seattle Mariners and the 66ers announced on January 20 in San Bernardino. Caballero joins the 66ers after leading the Modesto Nuts in 2025 and enters his 11th season in the Mariners organization; the club named him to guide Inland Empire as it returns to Seattle’s system as the Class-A California League affiliate.

Caballero’s appointment arrives with a defined coaching core. Josh Morgan, described as a former minor league catcher, will serve as Caballero’s bench coach for the second straight season, continuing a pairing that began in Modesto in 2025. Sam Delaplane joins Inland Empire as pitching coach in his first year as a coach; Delaplane was selected by Seattle in the 23rd round of the 2017 MLB First-Year Player Draft out of Eastern Michigan University and made it as high as Triple-A Tacoma as a player. Luke Carlson is listed as the strength and conditioning coach and Bryanna Brown as the athletic trainer, with the Mariners noting that any additional hires to the Inland Empire staff will be announced later.

The Mariners framed the announcement within a system-wide staffing release. “We are excited and proud to announce our affiliate staffs for the upcoming season,” Mariners Director of Player Development Justin Toole said, “From our ACL and DSL teams all the way up to Tacoma, we are confident that we have great fits to lead one of the best farm systems in baseball.” Inland Empire’s official Instagram also welcomed Caballero and his staff with the caption: “Welcome Luis to the IE @msplayerdev announce Luis Caballero as the club's manager and his staff for 2026. · Photo shared by Inland Empire 66ers.”

Inland Empire’s return to the Mariners is significant on multiple levels. The 66ers will play home games at San Manuel Stadium in San Bernardino and will open the 2026 schedule on April 7 vs. the Ontario Tower Buzzers at 6:35 p.m.; tickets will be available through the 66ers’ ticket office and the team’s online ticket portal. The franchise shifts class and affiliation after a long run as the Los Angeles Angels’ Triple-A affiliate from 2011–25; Inland Empire previously served as a Mariners affiliate from 1987–94 and 2001–06, making 2026 a clear organizational reunion.

Caballero brings playing and development credentials to a club looking to re-establish ties with Seattle. He signed with the Atlanta Braves as an amateur free agent from Panama in 2010 and appeared in 307 career minor league games with the Atlanta and Mariners organizations from 2010–15. The staff slate also signals an organizational emphasis on converting recent players into instructors: Delaplane’s jump from Triple-A player to first-year coach and Morgan’s back-to-back role with Caballero underscore the Mariners’ internal development pathway for coaches as well as players.

The full minor-league staff announcement includes other names in nearby text, including Chase Miller, Bryan Pall, Max Miller, and Blake Wooten; the provided excerpts tie Miller and Pall to the ACL Mariners in 2025, but those lines do not explicitly assign those four to Inland Empire for 2026. The Mariners and the 66ers said additional hires will be announced later, leaving open further staff additions as the club prepares for its April opener at San Manuel Stadium.