By far the biggest free agent splash of Jerry Dipoto’s tenure with the Mariners, Yusei Kikuchi is the latest Japanese import to don the navy and teal. At 27-years-old, Kikuchi has finally made the jump from the NPB to the MLB after spending eight seasons with the Seibu Lions.
While it took him time to adjust to the professional ranks, Kikuchi eventually established himself as one of the most dominant starting pitchers in the NPB circuit. He really began to turn heads after the best season of his pro career in 2017, when he posted career-highs in innings pitched (187.2), strikeouts (217), and ERA (1.97).
There is some risk attached to Kikuchi, however, as the southpaw has been sidelined several times due to injury concerns with his throwing shoulder throughout his career. The shoulder flared up once again in 2018, which held him out for three starts and seemed to have an affect on his overall performance during the season.
These health concerns will lead the Mariners to take several precautions in helping him adjust to the MLB lifestyle this season, including scheduled starts in which Kikuchi only appears for one inning. In a season in which they don’t aim to contend, the Mariners won’t attempt to push Kikuchi’s durability over the course of the longer MLB schedule (162 games) as opposed to NPB’s 143-game season.
For now, Kikuchi appears to have a relatively low ceiling of eventually being a #2 in some rotations with a high floor of being a #4 in others. It’s unlikely that he’ll reach the superstar status other Japanese players have found in Major League Baseball, and it’s unrealistic to expect him to have an ace-like impact on the Mariners’ rotation in 2019.
Instead, look for Kikuchi to properly continue his development, stay healthy, and adjust accordingly to the higher quality of hitters he’ll face every fifth day of the season. It’s an important first step in seeing whether the Mariners will pick up his four-year option after 2021, or be done with him after the 2022 season.