Still just 25, Walker debuted in the majors in 2011 as a highly touted prospect with the Mariners, who used a first-round pick on him the previous year. Walker didn’t quite live up to expectations during his time in Seattle, which dealt him to Arizona a year ago in a blockbuster that also featured Jean Segura, Mitch Haniger and Ketel Marte.
In his first season in Arizona, Walker rode a highly effective fastball to a 3.49 ERA over 157 1/3 innings, thereby aiding in the playoff-bound Diamondbacks’ unexpected resurgence. Walker also notched 8.35 K/9 against 3.49 BB/9 and recorded a 48.9 percent groundball rate, which helped him tamp down home runs. After giving up homers on 17.6 percent of fly balls in his Seattle swan song, he cut the number to a much more palatable 11.3 in 2017.
Walker’s output last season was worth $20MM, according to FanGraphs, making his $2.25MM salary a serious bargain. MLBTR’s Matt Swartz projects Walker to earn more than double last year’s amount ($5MM) in 2018, his second of four potential arbitration-eligible seasons.