The Mariners filled two openings on Jason Kanzler’s staff Monday, making official the hires of Tanner Swanson as bench coach and CJ Gillman as hitting coach.
“I am excited to have Tanner and CJ join our coaching staff,” Kanzler said in a release. “Both individuals bring an exceptional understanding of the game and skillsets that I am confident will help maximize the talent on our roster.”
Swanson arrives with deep ties to the region and a long track record in player development. The 44-year-old Roslyn native spent the last seven seasons with the Yankees, including the past three as their field coordinator and director catching. During that stretch, he helped Jose Trevino capture his first Gold Glove and Platinum Glove in 2022, and New York ranked second in baseball in fielding run value from catchers over Swanson’s seven seasons, according to Baseball Savant.
His baseball roots in Washington run deep. Swanson attended Cle Elum-Roslyn High School, then played at Green River College, Everett Community College and Central Washington University. He later taught and coached at Sultan High School.
Swanson’s coaching path started in college ball, first as an assistant at Everett Community College in 2009 and then at CWU in 2010. He became Green River College’s head coach in 2011 and later served as a volunteer assistant for the UW Huskies from 2013-17.
He also comes from a notable baseball family. Swanson is the son of Jim Swanson, the legendary left-handed catcher for the Portland Mavericks minor league team in the 1970s.
Gillman is back in Seattle after a year away. The 37-year-old spent 2026 as the Washington Nationals’ director of hitting after working as the Mariners’ minor league hitting coordinator from 2022-25. This will be his first full-time job on a major league coaching staff.
Before his first run with Seattle, Gillman held the same minor league hitting coordinator role with the Cincinnati Reds from 2020-21. He also worked as the Air Force Academy baseball team’s head of recruiting from 2015-19, along with other roles.
Gillman played two seasons at Garden City Community College in Kansas and two more at the University of Dayton before spending two years in independent ball in the Frontier League.
The two hires account for half of the Mariners’ four open coaching spots after the club parted ways with bench coach Manny Acta, infield coach Perry Hill, hitting coach Kevin Seitzer and first base coach Eric Young Jr. Seattle still has not announced replacements for the infield coach and first base coach jobs.
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