The 26-yer-old O’Brien has drawn his fair share of attention over the years due to his gaudy power numbers in Triple-A. In 968 plate appearances at that level — split between the Yankees and Diamondbacks — O’Brien has compiled a career .270/.315/.530 batting line. Originally acquired by the D-backs in the 2014 trade that sent Martin Prado to the Yankees, O’Brien has slugged a total of 50 home runs in parts of two seasons in Triple-A.
While O’Brien began his career as a catcher, few scouts gave him much of a chance to stay behind the plate due to defensive concerns. Many scouting reports have suggested that O’Brien lacks any real position on the defensive spectrum, and he’s struggled in his brief taste of the Major Leagues to date (.176/.228/.446 with six homers but 32 strikeouts in 79 plate appearances). Still, he’ll give the Royals a potential power bat with multiple years of club control remaining. Unlike the D-backs, the Royals can simply elect to play O’Brien at DH in the event that he does eventually see his big league production more closely mirror the work he’s put in at the Triple-A level.
Lewis, meanwhile, turned 25 this offseason and returned from a 2015 injury to log 44 1/3 innings of 1.62 ERA ball across three minor league levels. However, impressive as that number seems, it should be noted that he topped out at Class-A Advanced, so he was working against considerably younger and less experienced competition. Lewis averaged 7.9 K/9 against 1.4 BB/9 in his 2016 campaign while also posting a 47.5 percent ground-ball rate, per MLBfarm.com. Their notes on Lewis have his fastball in the upper 80s to low 90s. Lewis only totaled nine innings at High-A last season, and that was his first exposure to the level, so he could return there to open the 2017 season or be pushed to Double-A if the D-backs take a bit more aggressive approach. He’s made just nine minor league starts, so he’s likely viewed strictly as a reliever by his new organization.