SEATTLE -- The Mariners added some veteran depth to their bullpen on Thursday, signing free-agent reliever Yoshihisa Hirano to a one-year Major League contract.

After an 11-year career in Japan, Hirano spent the past two seasons with the D-backs and posted a 9-8 record and 3.47 ERA with four saves in 137 appearances. The right-hander racked up 120 strikeouts in 119 1/3 innings with a 90-92 mph fastball and quality splitter combination.

To make room on the 40-man roster for Hirano, the Mariners designated left-hander Ricardo Sánchez for assignment. Sánchez went 8-12 with a 4.44 ERA in 27 starts for Double-A Arkansas last season.

According to MLB Network insider Ken Rosenthal, Hirano is guaranteed a $1.6 million base salary, plus potential performance bonuses that could add an additional $950,000 based on number of appearances and games finished. Hirano would also receive $250,000 if he's traded.

The 35-year-old Hirano could be in the mix for late-inning duty with a Mariners club that doesn’t have any proven closers, joining holdovers Matt Magill and Sam Tuivailala as likely candidates for ninth-inning work. Austin Adams, another potential closing candidate, will be sidelined until midseason as he recovers from right knee surgery from an injury sustained on the final road trip of 2019.

“We’re glad to have Yoshi on board,” Mariners general manager Jerry Dipoto said. “We believe his combination of experience and bat-missing ability brings needed stability to our bullpen.”

Hirano worked as the closer for most of his final five seasons for the Orix Buffaloes in Japan’s Pacific League, totaling 156 saves, including a league-leading 40 in 2014.

The 6-foot-1, 185-pounder had an outstanding debut season for the D-backs in 2018, when he put up a 2.44 ERA and three saves in 75 outings. He finished sixth in National League Rookie of the Year Award voting. His strikeout numbers increased last year, with 61 in 53 innings, but his ERA also jumped to 4.75 and his WHIP increased from 1.085 to 1.377.

Hirano went on the 10-day injured list in mid-August with right elbow inflammation, but he returned after a three-week shutdown to pitch effectively in seven games in September. He became a free agent on Oct. 31 at the end of his initial two-year, $6 million deal.

The Mariners are hopeful that Hirano can bolster their bullpen as well as be a good influence for Yusei Kikuchi, their 28-year-old Japanese starter who struggled through an inconsistent rookie season last season.

Hirano becomes the 11th Japanese player to sign with Seattle over the years, joining fellow pitchers Kikuchi, Mac Suzuki (1996, '98-99), Kazuhiro Sasaki (2000-03), Shigetoshi Hasegawa ('02-05), Masao Kida ('04-05) and Hisashi Iwakuma ('12-17), outfielders Ichiro Suzuki ('01-12, '18-19) and Norichika Aoki ('16), catcher Kenji Johjima ('06-09) and infielder Munenori Kawasaki ('12).

Hirano is the second free-agent reliever signed this offseason by Dipoto, who also inked former Cubs right-hander Carl Edwards Jr. to a one-year, $950,000 deal in December. The other free agents added this winter have been starter Kendall Graveman and infielder Patrick Wisdom.