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Jorge Polanco of the Minnesota Twins is out at second base as Shawn O’Malley of the Seattle Mariners turns a double play during the first inning of the game.
Triple-A hitting coach Shawn O’Malley has reportedly left the Seattle Mariners organization and joined the Washington Nationals.
The 37-year-old Washington native was listed as the Nationals’ Assistant Hitting Coach in a post shared on Tuesday. The change signals a move from Seattle’s minor league system to a major league role in Washington D.C.
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O’Malley leaves the Mariners after a successful playing career followed by a steady rise through the organization’s coaching ranks. He ended with a successful stint as hitting coach for the Tacoma Rainiers, Seattle’s Triple-A affiliate.
From Player to Coach
In the fifth round of the 2006 MLB Draft, the Tampa Bay Rays selected Shawn O’Malley. He made his major league debut with the Los Angeles Angels in 2014. He then spent parts of two seasons with the Mariners.
Previously, the switch-hitting utility man appeared in 124 big league games over three seasons. This includes 113 with Seattle between 2015 and 2016. He enjoyed an active 2016 season with the Mariners, appearing in 89 games in multiple positions as a versatile defender.
For his career, O’Malley hit .231 with three home runs and 11 stolen bases. He carved out a role as a dependable utility player. He celebrated one of the most memorable nights of his playing career on the same night Ken Griffey Jr. became the first player in history to have his number retired by the Mariners. That evening, O’Malley hit a three-run homer, securing an important win for Seattle during a playoff race.
Following his playing career, O’Malley transitioned into coaching in 2020. He joined the Mariners organization as a minor league hitting instructor and steadily worked his way up.
Time with the Mariners
During his time with the team, O’Malley had great impact on the Rainiers. In 2025, he achieved the Dave Henderson Minor League Staff Member of the Year by the Mariners after helping Tacoma capture the second-half Pacific Coast League championship.
With his help, the Rainiers hitters ranked among the best in the league, finishing fourth in hits (1,455), third in RBIs (885), third in walks (704), and second in on-base percentage (.375).
Beyond team success, O’Malley played a role in the developing several important Mariners players and prospects. He worked closely with Dominic Canzone, helping spark significant offensive improvements. He also helped with the development of top prospects Cole Young and Harry Ford.
Earlier, in August, he spoke on about Canzone who was recalled by Seattle on June 9. Canzone hit .300 with 11 home runs.
“Like, this is a ’we’ thing. So a lot of it was looking at his old swing, finding out, like, ’hey, what do you want to do?’ This is your career. How can I help you moving forward?’ So a lot of it was just walking back to things that he’s learned in the last few years, but also going back to what got him there in the first place.”
This departure marks another offseason change within the Mariners’ organization following their 2025 success. Third base coach Kristopher Negrón left for the Pittsburgh Pirates’ bench coach position, while bullpen coach Tony Arnerich was hired as the Cleveland Guardians’ bench coach. Additionally, Mariners assistant general manager Andy McKay joined Cleveland as its field coordinator.
Sydney Jones Sydney Jones is a sports writer covering all things Golf, Mariners, and Seahawks for Heavy.com. She has experience covering the intersection of sports and human interest stories for multiple publications. Originally from Montana, she recently relocated to Seattle and is enjoying the new experience of being surrounding by live professional sports and rooting for a common team while writing about them. More about Sydney Jones
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