On Tuesday, the Miami Marlins announced their full major league coaching staff for the 2026 season.
Four coaches from the previous season have departed the organization after receiving promotions from other MLB teams—Derek Shomon (Chicago White Sox), Joe Singley (Baltimore Orioles), Tyler Smarslok (Washington Nationals) and Alon Leichman (Colorado Rockies). To fill their shoes, manager Clayton McCullough has added Blake Butler, Craig Driver, Corbin Day, Chris Hess and Rob Marcello.
Here are notes about each of the newcomers and what their job responsibilities will be in Miami.
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Blake Butler, infield coach
Previously with the Pittsburgh Pirates organization, Butler began his coaching career in 2020. During his six-year stretch in the organization, he led High-A Greensboro to consecutive playoff appearances as a minor league manager (2024-25), including an 88-43 record last season. Butler is also a former player who selected in the 2015 MLB Draft by the Cincinnati Reds and made it to the High-A level as a utility guy.
Butler is partially replacing Smarslok, who handled infield and baserunning instruction last year while also serving as first base coach.
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Corbin Day, assistant hitting coach
Day spent the 2025 season with the Minnesota Twins organization . His most recent role was as an advanced scout for run production. Prior to that, he was in the Twins minor league system as the hitting coach for High-A Cedar Rapids in 2023 and Double-A Wichita in 2024. During his High-A stint, the Kernels led the Midwest League in triples (41), homers (137), runs (694), walks (634), on-base percentage (.340) and OPS (.738).
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Craig Driver, first base coach and catching instructor
Driver comes from the Los Angeles Dodgers organization where he overlapped with current Clayton McCullough in 2024. Before that, he spent four seasons with the Chicago Cubs (2020-23), working as a first base and catching coach while also doing game strategy. Prior to his time with the Cubs, he was the bullpen catcher for the Philadelphia Phillies during the 2018-19 seasons, overlapping with Marlins general manager Gabe Kapler, who was the Phillies manager back then.
As Joe Singley’s successor, Driver has a big job ahead of him overseeing the defensive development of Marlins youngsters Joe Mack, AgustÃn RamÃrez and Liam Hicks.
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Chris Hess, assistant hitting coach
A former New York Yankees farmhand who spent three seasons with the organization after being selected in the 2017 MLB Draft, Hess began his coaching career at the University of Rhode Island. He switched to the professional side with the Boston Red Sox in 2021. He worked his way up to Double-A hitting coach before being hired by the Marlins.
Hess and Day will combine to handle the duties that previously belonged to Shomon.
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Rob Marcello, assistant pitching coach
Unlike the names above, Marcello has been promoted from within. He spent the 2025 season as pitching coach of the Jacksonville Jumbo Shrimp, who won the International League Championship and Triple-A National Championship. That means he has directly worked with many members of the current Marlins pitching staff as well as top prospects who are projected to debut next year, including Thomas White, Robby Snelling and Josh White.
Outgoing assistant pitching coach Alon Leichman was responsible for relaying signs to the catcher when the Marlins decided to call pitches from the dugout at the major league level. We haven’t received confirmation yet on whether Marcello will be doing that in 2026, but he’s fully familiar with the process because it was implemented across all Marlins MiLB affiliates.