Marlins Option Prospects Joe Mack, Ryan Gusto to Triple-A Jacksonville

Joe Mack arrived at Marlins camp this spring as Miami's most closely watched prospect, a 23-year-old catcher ranked No. 62 overall by MLB Pipeline who had just been added to the 40-man roster to protect him from the Rule 5 Draft. He left Jupiter on March 15 headed back to Triple-A Jacksonville, batting .125 with seven strikeouts in 24 at-bats.

The Marlins optioned Mack and right-hander Ryan Gusto to Jacksonville as part of their latest round of spring cuts. Miami also reassigned Kemp Alderman, the organization's No. 9 prospect, along with righty relievers Zach Brzykcy and Jack Ralston to Minor League camp.

Despite the quiet spring numbers, manager Clayton McCullough remained firmly in Mack's corner. "Joe's coming off a terrific year, especially [when] you take into account the position he plays, age for level, for a high school catcher to get up to Triple-A at his age-22 season," McCullough said. "He's on a really, really good trajectory, and [on] the defensive side of the ball, we know he can catch, he can throw. I think the timing of the WBC was probably [in] a lot of ways perfect. It gave Joe a lot of opportunities, chances to catch a lot of pitchers that are going to either start with us, or certainly that he'll be handling in Jacksonville."

Mack's expanded playing time this spring came directly from the World Baseball Classic. With projected Opening Day backstops Agustín Ramírez and Liam Hicks representing the Dominican Republic and Canada, respectively, Mack stepped into a primary role in nine Grapefruit League games. He hit a grand slam and threw out two baserunners, but managed just three hits overall and went 2-for-4 in automated ball-strike challenges, numbers that reinforced existing concerns about his contact abilities.

Those concerns trace back to his 2025 season at Triple-A Jacksonville, where Mack's .250/.320/.459 slash line, 18 homers and 53 RBIs across 100 games told an impressive story for a young catcher on the rebound from just 13 Double-A games at Pensacola. But he struck out 115 times against only 35 walks, producing a 27.9% strikeout rate that scouts have flagged consistently. His 107 wRC+ with the eventual Triple-A national champions was solid, not spectacular, for a player with top-100 billing.

The team's preference was always for Mack to open 2026 in Jacksonville and refine his approach at the plate, including greater familiarity with the automated ball-strike system. Catching duties in Miami will fall to Ramírez and Hicks. Ramírez, acquired from the Yankees in the Jazz Chisholm Jr. trade at the 2024 deadline, slugged 21 homers in 136 games last season but posted a .287 on-base percentage for a 91 wRC+. Hicks, Miami's 2024 Rule 5 selection, produced a 98 wRC+ in 119 games behind the plate, though lackluster defensive metrics left him worth just 1.0 fWAR.

Gusto's path back to the majors runs through Jacksonville as well, but under different circumstances. Acquired from the Astros last year, Gusto posted a 9.77 ERA across three spring starts and will head to the minors as rotation depth rather than pivot to a bullpen role. The Marlins were explicit that a position switch is not part of the plan.

For Mack, the assignment is a return to familiar ground. He helped Jacksonville win a Triple-A national championship last year, and the Marlins view another full season there as the development step most likely to sharpen the one tool that could separate a good prospect from a big-league regular.