Mariners Sign Japanese Reliever Shintaro Fujinami to Minor League Deal

SEATTLE, Wash. — The Seattle Mariners have signed Japanese right-handed reliever Shintaro Fujinami to a minor league contract with an invitation to spring training, according to MLB Network insider Jon Morosi. The 30-year-old flamethrower, known for his blistering fastball and swing-and-miss potential, will join the Mariners’ camp as a non-roster invitee.

Fujinami, who turns 31 in April, made his MLB debut in 2023 with the Oakland Athletics after a decade in Japan’s Nippon Professional Baseball (NPB) league. Despite a rocky start in Oakland, where he allowed 24 runs in his first 15 innings, he found success in the bullpen, posting a 3.32 ERA and a 25.6% strikeout rate over his final 21 2/3 innings before being traded to the Baltimore Orioles. His fastball averaged an impressive 99.5 mph during that stretch.

After a midseason trade to Baltimore, Fujinami initially thrived, recording a 3.76 ERA in his first 26 1/3 innings. However, he struggled in his final appearances, finishing his Orioles tenure with a 4.85 ERA. Despite the inconsistency, his underlying metrics, including a 15% swinging-strike rate, caught the attention of the New York Mets, who signed him to a one-year deal last winter.

Injuries derailed Fujinami’s 2024 season, as shoulder issues limited him to minor league rehab stints. He posted a 1.85 ERA in 24 1/3 innings in the minors but saw a dip in velocity, with his fastball averaging 97.3 mph, down from his 2023 peak. Fujinami rebounded in the Puerto Rican Winter League, where he logged a 3.05 ERA and a 26.7% strikeout rate in 20 2/3 innings, earning another shot at the majors.

The Mariners, known for uncovering bullpen gems, hope Fujinami can stabilize their relief corps. Seattle’s bullpen is anchored by star closer Andrés Muñoz, with several options vying for setup roles. Fujinami’s high-velocity fastball and strikeout potential make him an intriguing addition, though his command issues remain a concern.

Before joining MLB, Fujinami was a four-time NPB All-Star and a member of Team Japan in the 2017 World Baseball Classic. Over 189 NPB games, he compiled a 57-54 record with a 3.41 ERA and 1,011 strikeouts in 994 1/3 innings.