The New York Yankees are preparing to lose a key member of their coaching staff, with longtime catching coordinator Tanner Swanson reportedly moving to the Seattle Mariners to become their bench coach. The reported appointment, which emerged on November 6, would place Swanson on the coaching staff of newly appointed Mariners manager Jason Kanzler and mark a significant expansion of his responsibilities in Major League Baseball.

MLB.com reported Friday that Seattle was in the process of hiring Swanson, citing a source familiar with the situation. The report identified him as the Mariners’ expected replacement for Manny Acta, who will not return as the club’s bench coach for the 2027 season. However, the Mariners had not officially confirmed the hiring as of November 6. The development follows an earlier report by New York Post baseball columnist Joel Sherman, whose reporting was also cited in MLB.com’s coverage.

Swanson has been a member of the Yankees’ major league coaching staff since 2020. He initially served as the organization’s quality control and catching coach while overseeing its catching development program. His responsibilities subsequently expanded, and he became the club’s Major League field coordinator in 2024. The Yankees’ official 2026 coaching staff announcement listed him in both positions, reflecting the broader responsibilities he had accumulated during his tenure in New York.

His departure would represent a notable loss for the Yankees because of the measurable defensive improvements associated with their catching program. According to MLB.com, New York’s catchers have accumulated 86 catcher framing runs since Swanson joined the organization in 2020, the highest total in Major League Baseball over that period. The group also ranked 11th in blocks above average, with a cumulative figure of plus-five, according to the same report.

Those results reflect the growing importance of catcher defense in modern baseball. Pitch framing involves a catcher’s ability to receive pitches in a way that helps borderline deliveries appear more likely to be called strikes. Even small differences in how catchers receive pitches can influence at-bats, pitch counts and the workload placed on pitchers. Framing statistics have therefore become an important tool for evaluating defensive contributions that traditional fielding statistics may not fully capture.

The Yankees’ own assessment of Swanson’s work also highlighted the program’s long-term results. In their December 2025 announcement of the 2026 coaching staff, the organization reported that its catchers had accumulated 73 catcher framing runs since 2020, ranking first in the majors at that time. The same announcement placed the group second in shadow strike rate, at 48.6%, and third in defensive runs saved, with 39. Those figures covered the period through the 2025 season and provided an indication of the defensive foundation Swanson helped establish before the latest season.

For Seattle, the appointment would add an experienced major league coach to a staff undergoing substantial changes. The Mariners appointed Kanzler as their new manager on November 4, following the conclusion of Dan Wilson’s tenure. Kanzler, 36, previously served as the Chicago Cubs’ director of player development for three seasons and worked in the Houston Astros organization before joining Chicago. His appointment represents a different managerial direction for Seattle, with an emphasis on player development, communication and organizational coordination.

The Mariners had already announced that several members of Wilson’s previous coaching staff would not return for 2027. Alongside Acta, the departing coaches included infield coach Perry Hill, hitting coach Kevin Seitzer and first-base coach Eric Young Jr. Seattle announced those changes on September 28, explaining that the incoming manager would have an opportunity to shape the coaching staff. Swanson’s reported arrival would therefore be part of a broader effort to establish the leadership structure Kanzler will work with during his first season as manager.

The bench coach position is particularly important within a major league dugout. Typically serving as the manager’s closest coaching aide, a bench coach contributes to game preparation, strategic discussions, communication with players and the coordination of daily baseball operations. Swanson’s move from a specialized catching position to this broader role would place his experience in a different organizational context. His previous work as a Major League field coordinator may also provide relevant experience beyond the specific technical responsibilities of catching instruction.

Swanson also has longstanding connections to the Pacific Northwest. He is a Washington state native and graduated from Central Washington University. Before joining the Yankees, he spent two seasons, from 2018 through 2019, as the Minnesota Twins’ Minor League catching coordinator. Earlier in his career, he worked at several collegiate baseball programs, including a five-year period as a volunteer assistant coach at the University of Washington from 2013 through 2017. His professional coaching background therefore developed largely in the region where Seattle is based.

The Mariners’ decision would also bring a specialist with extensive experience in catcher development into a more prominent position within the major league organization. Seattle’s coaching staff will need to coordinate its work across pitching, catching, defense and player development as the club prepares for the 2027 season. Swanson’s experience working with major league catchers and coordinating broader field operations could provide continuity in those areas while Kanzler establishes his managerial approach.

For the Yankees, the immediate consequence is the departure of a coach who has been closely associated with one of the organization’s strongest defensive development programs. His work has extended across multiple seasons and different groups of catchers, making his exit more significant than a routine offseason coaching change. New York will have to determine how to distribute his previous responsibilities and maintain the systems developed during his tenure. The organization has not announced a replacement in connection with the November 6 report.

For Swanson, the reported move offers an opportunity to advance from a specialized coaching position into a major league bench leadership role. It also represents a return to Washington, where he began building his professional coaching career. The Mariners, meanwhile, would gain a coach with seven seasons of experience on the Yankees’ major league staff as they assemble a new coaching group around Kanzler.

Although the appointment remained unconfirmed by Seattle on November 6, the reports indicate that Swanson is expected to become an important part of the Mariners’ 2027 leadership structure. His transition highlights the continuing movement of coaching talent across MLB and the increasing value organizations place on defensive development, analytical evaluation and experienced major league staff leadership.