The Miami Marlins are reshaping their coaching staff heading into the 2026 season, and Tuesday’s announcement gave us a clear look at the new faces joining manager Clayton McCullough’s dugout. With four coaches from last year’s staff moving on to new opportunities elsewhere in Major League Baseball, the Marlins are turning the page with a mix of internal promotions and fresh hires from across the league.
Who's Out, Who's In
Derek Shomon, Joe Singley, Tyler Smarslok, and Alon Leichman have all left the organization after earning promotions with other MLB clubs. In response, Miami has added Blake Butler, Craig Driver, Corbin Day, Chris Hess, and Rob Marcello to the big-league coaching staff. Each brings a unique background and set of skills to the table, and collectively, they’ll be tasked with helping guide a young, developing Marlins roster through the next phase of its rebuild.
Let’s break down what each of these new coaches brings to the Marlins and how they fit into the 2026 puzzle.
Blake Butler: Infield/Baserunning Coach & First Base Coach
Butler steps into a role that partially replaces what Tyler Smarslok handled last season - infield and baserunning instruction, along with first base coaching duties. He arrives from the Pittsburgh Pirates organization, where he’s been steadily climbing the coaching ranks since 2020. Most recently, he managed High-A Greensboro to back-to-back playoff appearances, including a standout 88-43 record in 2025.
Butler’s blend of recent managerial success and playing experience - a former utility player drafted by the Reds in 2015 - gives him a well-rounded perspective. His ability to connect with players and teach fundamentals should serve him well, especially with a Marlins team that’s still developing its core. Expect Butler to have a strong hand in sharpening the team’s infield defense and aggressive baserunning approach.
Corbin Day: Assistant Hitting Coach
Day joins the Marlins from the Minnesota Twins, where he most recently worked as an advanced scout focused on run production. That title might sound niche, but it speaks to his analytical chops and understanding of how to generate offense in today’s game. Before that, he spent time as a hitting coach in the Twins’ system, including a stint in 2023 with High-A Cedar Rapids - a team that led the Midwest League in nearly every major offensive category: triples, home runs, runs, walks, OBP, and OPS.
That kind of offensive output doesn’t happen by accident. Day brings a data-driven approach to hitting instruction, but he also knows how to translate that into results on the field. He’ll be working alongside fellow new hire Chris Hess to fill the void left by Derek Shomon.
Craig Driver: First Base Coach & Catching Instructor
Driver’s resume is packed with experience at the highest levels of the game. He comes over from the Dodgers, where he previously overlapped with McCullough in 2024.
Before that, he spent four seasons with the Cubs as a first base and catching coach, also contributing to game strategy. Go back even further, and you’ll find him in Philadelphia as the bullpen catcher during the 2018-19 seasons - a role that connected him with current Marlins GM Gabe Kapler.
Driver will take over the catching department from Joe Singley, and that’s no small task. He’ll be responsible for the continued development of young backstops like Joe Mack, Agustín Ramírez, and Liam Hicks. With his background and experience, Driver is well-equipped to mold that next wave of Marlins catchers into strong defensive anchors behind the plate.
Chris Hess: Assistant Hitting Coach
Like Day, Hess will be part of the new-look hitting instruction team in Miami. A former Yankees prospect, Hess transitioned into coaching after his playing days and cut his teeth at the University of Rhode Island before joining the Red Sox organization in 2021. He rose through the ranks quickly, eventually becoming a Double-A hitting coach.
Hess brings a player’s perspective and a teacher’s mindset. His experience in the minors - both as a player and coach - gives him a strong foundation for connecting with hitters still learning how to adjust at the big-league level. He and Day are expected to work in tandem, combining modern analytics with on-field instruction to help elevate the Marlins’ offensive production.
Rob Marcello: Assistant Pitching Coach
Marcello is the lone internal promotion among the new hires, moving up from Triple-A Jacksonville, where he served as pitching coach during the Jumbo Shrimp’s championship-winning 2025 season. That means he’s already familiar with much of the Marlins’ current pitching staff - and perhaps more importantly, with the top prospects expected to make their MLB debuts soon, including Thomas White, Robby Snelling, and Josh White.
Marcello’s promotion keeps continuity within the organization’s pitching philosophy, especially as Miami continues to lean on its farm system for arms. While it’s unclear if he’ll inherit the exact responsibilities of outgoing assistant pitching coach Alon Leichman - who handled pitch-calling communication from the dugout - Marcello has experience with that system, which has been implemented throughout the Marlins’ minor league affiliates.
What This Means for the Marlins
This new coaching group reflects a clear organizational strategy: blend experience with player development expertise. There’s a heavy emphasis on coaches who’ve worked closely with young talent, which makes sense for a Marlins team still building toward long-term contention. Whether it’s refining the approach at the plate, tightening up the defense, or grooming the next wave of pitchers and catchers, this staff is designed to grow with the roster.
There’s no guarantee of immediate results, but the foundation is being laid. With McCullough at the helm and a new staff ready to get to work, the Marlins are betting on continuity, communication, and a clear developmental path to help them take the next step in 2026.