On the eve of Spring Training, the Seattle Mariners re-signed right-handed pitcher Taijuan Walker to a one-year major league contract, reported to be worth $2 million. The former 43rd overall pick by the Mariners in 2010 was the centerpiece of one of general manager Jerry Dipoto’s earliest of many trades in Seattle when Walker and former shortstop Ketel Marte were sent to the Arizona Diamondbacks in exchange for Jean Segura and Mitch Haniger.
Then age 23, Walker was considered a blossoming prospect. In 2016 with the Mariners, Walker started 25 games and pitched 134.1 innings. He pitched to a 4.22 ERA, a drop of 0.34 from the 2015 season, and struck out 119 hitters. In his one full season with the Diamondbacks during 2017, Walker started 28 games and pitched 157.1 innings for a 9-9 record, 146 K, and a 3.49 ERA, which translated into an impressive 135 ERA+.
In mid-April of the 2018 season, Walker went on the IL with forearm tightness that was then diagnosed as a partial tear of his UCL. Tommy John surgery followed, and Walker would only pitch one more game in a Diamondbacks’ uniform, the last game of the 2019 season. During the winter, the Diamondbacks non-tendered Walker and he became a free agent.
According to MLB Trade Rumors, several other clubs had shown interest in the still relatively young former prospect including the Chicago Cubs. Presumably, Walker will slot into the rotation as either the four or the five behind Marco Gonzales, Yusei Kikuchi, and Justus Sheffield, while competing with recently acquired Kendall Graveman, also returning from Tommy John surgery.
Given Walker’s recent injury history, most of the projection models are understandably conservative on what his 2020 production might look like. Both Depth Charts and Steamer are identical in their forecast for Walker, with 117.0 innings, a 6-8 record, 7.70 K/9, 3.00 BB/9, 4.97 ERA, and worth 0.7 WAR. Early ZiPS projections which look primarily at player WAR had come out for the Mariners prior to the signing, but for comp purposes placed Graveman at 0.8 WAR, roughly where Walker is being projected.
Given the modest expectations for this season’s Mariners team, Seattle may be one of the best places for a once high-end prospect to return to the majors following injuries that have kept him out of action for all but 14.00 innings the past two seasons. With little risk to the club, perhaps the Mariners have found a future pitching star, again.