1 internal hire, 5 newcomers complete Marlins' 2026 coaching staff

December 16th, 2025

MIAMI – The Marlins finalized manager Clayton McCullough’s 2026 coaching staff, which features five newcomers after some turnover.

Chris Hess and Corbin Day join Pedro Guerrero on a three-person hitting staff – the first for Miami since 2024 – while Craig Driver takes over as the first-base and catching coach, Blake Butler as the infield coach and Rob Marcello as the assistant pitching coach.

Marcello, who is the only internal hire, served as Triple-A Jacksonville’s pitching coach during its national championship-winning 2025 season. The Jumbo Shrimp’s staff led the International League in ERA (3.73) and opponents’ average (.228), tied for the most saves (44), posted the second-lowest WHIP (1.28), collected the fifth-most strikeouts (1,344) and issued the fifth-fewest walks (570).

This past season marked Marcello’s first in the Marlins’ organization after stints as a volunteer assistant at Indian River State College, where he also began his collegiate playing career before transferring to Appalachian State; pitching coach with High-A Modesto (2019) and Triple-A Tacoma (‘21) in the Mariners’ organization; and the Padres’ director of pitching from October 2021 through January 2025.

Marcello, 35, has South Florida roots, having attended nearby Royal Palm Beach Community High School. A 17th-round pick of the Phillies in the 2013 MLB Draft, he compiled a 5.55 ERA in 18 relief appearances in his lone Minor League season for Short Season Class A Williamsport.

Keeping the assistant pitching coach job internal provides two obvious benefits to Miami.

Marcello has familiarity with top prospects Thomas White (Marlins’ No. 1, No. 22 overall), Robby Snelling (No. 3, No. 51 overall) and Dax Fulton (No. 13), all of whom completed the 2025 season at the Triple-A level. Plus, Marcello was part of the organization-wide effort to call pitches from inside the dugout, something the Marlins introduced on the Major League side during the season’s final week. Assistant pitching coach Alon Leichman had been in charge of doing so, but he recently left to become the Rockies’ pitching coach.

Leaving the Marlins for promotions elsewhere were Leichman, assistant hitting coach Derek Shomon (White Sox hitting coach), catching coach/assistant catching director/bullpen catcher Joe Singley (Orioles field coordinator) and infield/baserunning/first-base coach Tyler Smarslok (Nationals field coordinator). All four had been in his first year with the Marlins' organization.

Returning are bench coach Carson Vitale, Guerrero, pitching coach Daniel Moskos, third-base/outfield coach Blake Lalli, field coordinator Aaron Leanhardt, bullpen coach Brandon Mann and Major League strategist Bryson Nakamura.