Marlins poised to call up Joe Mack, send Agustin Ramirez to Triple-A

Miami’s catcher problem has boiled down to one brutal number: three runners thrown out in 45 stolen-base attempts, a rate that exposed just how badly the Marlins needed a different answer behind the plate.

That answer is Joe Mack. The 22-year-old left-handed hitter and right-handed thrower was expected to move to Miami before Monday’s game against the Phillies, with MLB.com reporting Sunday that the club had not yet made it official. Mack is already on the 40-man roster, which makes the move clean from a roster standpoint, and it reflects how quickly his stock has risen since Miami added him on Nov. 21, 2025. He was the club’s No. 4 prospect then and ranked No. 70 overall; MLB Pipeline now has him at No. 4 in the organization and No. 62 overall, while MLB.com’s updated call-up note pegged him as a Top 100 prospect and No. 54 overall.

The Marlins drafted Mack 31st overall in 2021 out of Williamsville East High School in New York and signed him for $2.5 million. They have leaned into the defensive side of his profile for good reason. He won a 2024 Minor League Rawlings Gold Glove Award at catcher, threw out 28 of 88 attempted base stealers in Triple-A Jacksonville last season, and has posted a 29 percent caught-stealing rate in 23 games behind the plate this year, above the International League average of 22 percent. Even with a modest Triple-A line this season, .224 with three homers, six RBIs and one steal in 67 at-bats, the glove has kept him on the fast track.

Agustín Ramírez is the one paying for the collapse. In 2025, he led major league catchers with 19 passed balls and 10 errors, allowed 83 steals, and threw out only eight of 91 base stealers. MLB.com’s defensive metrics were even harsher, putting him in the 1st percentile in blocks above average at minus-28. Offensively, Ramírez gave Miami plenty to dream on, becoming the fourth Marlins catcher ever to steal 10 bases in a season while tying the club record for home runs by a catcher with 21 and extra-base hits by a catcher with 55.

That bat is exactly why this is not a simple demotion. Through 30 games this season, Ramírez was hitting .239 with two homers and 14 RBIs, but the Marlins also need him to become a catcher they can trust. Back in Jacksonville, that means cleaner blocking, better control of the running game and fewer of the mistakes that turned every extra baserunner into a threat. Liam Hicks, with seven homers, 29 RBIs and a .309 average entering Sunday, will keep forcing at-bats somewhere in the lineup. Ramírez’s path back runs through Triple-A, and this time the glove has to catch up to the power.