Heading into the offseason, the Seattle Mariners are focusing on bolstering their bullpen, an area identified as a critical positional need. Despite expectations for improvement in 2024, the depth of the relievers remains a concern. The team is optimistic about Matt Brash’s recovery from Tommy John surgery, which is ahead of schedule and expected to see him return early in April. Gregory Santos is also anticipated to be fit after a challenging previous season filled with injuries.

Recently, the Mariners added Shintaro Fujinami to their roster and further strengthened their bullpen by acquiring right-handed reliever Will Klein from the Oakland Athletics in exchange for international slot money, effectively adding him to the 40-man roster. In a corresponding move, left-handed reliever Tyler Jay was designated for assignment. Klein, initially drafted by the Kansas City Royals, had a rocky MLB debut last season with a 6.35 ERA in five appearances, followed by a difficult stint with the Athletics where he posted a staggering 27.00 ERA over three games. While Klein's initial statistics are concerning, the Mariners are known for their capability to develop pitchers, suggesting they might extract better performance from him.

The Seattle Mariners have signed veteran reliever Neftali Feliz to a minor-league contract, providing much-needed bullpen assistance. Feliz, a former AL Rookie of the Year and All-Star, has a notable history with the Texas Rangers, where he achieved significant success in 2010.

At 36, Feliz has not pitched in the majors since 2021 but is currently performing well in the Dominican Winter League. This low-risk signing aims to bolster the Mariners' bullpen after recent departures.

The Seattle Mariners are currently participating in the MLB Winter Meetings in Dallas, focusing on potential acquisitions, including Japanese star Roki Sasaki. However, they have yet to make any significant moves.

In a notable development, veteran reliever Yimi Garcia has returned to the Toronto Blue Jays after signing a two-year contract worth $15 million. Garcia's tenure with the Mariners was marred by injuries, limiting his effectiveness.

Despite the setback with Garcia, the Mariners have opportunities to strengthen their bullpen, especially with the return of Matt Brash from surgery and the potential emergence of top prospect Brandyn Garcia in the future.

During the winter meetings in Dallas, Seattle Mariners President of Baseball Operations Jerry Dipoto provided updates on pitchers Matt Brash and Jackson Kowar.

Brash is ahead of schedule in his recovery from Tommy John surgery and could return by late April, adding significant strength to the bullpen. Kowar is on track for his return, as the Mariners hope to develop him into a reliable pitcher.

The Seattle Mariners are experiencing a significant loss in their organization as minor league pitching coordinator Matt Pierpont departs for a prominent position with the St. Louis Cardinals. This marks the second consecutive year the Mariners have lost a key pitching coordinator, raising concerns about a 'brain drain' as other teams seek to capitalize on the Mariners' successful player development.

Pierpont expressed gratitude for his time with the Mariners, highlighting the honor of working with talented individuals. The Mariners have successfully developed pitchers like Logan Gilbert, George Kirby, Bryce Miller, and Bryan Woo, contributing to one of the strongest starting rotations in Major League Baseball.