A Rule 5 pick last winter, Keller spent the first couple months in the Royals' bullpen before transitioning to a starting role. He was one of Kansas City's most effective arms down the stretch, posting a 2.25 ERA and 1.17 WHIP over his final eight starts (52 innings), bringing his season ERA down to a shiny 3.08. The right-hander achieved that mark despite a middling 6.2 K/9 and 3.2 BB/9 -- his 7.9 K-BB% ranked 85th among 88 pitchers with 140 innings. What he lacked in terms of dominance he made up for with groundballs (54.4%), and in turn limiting homers (0.45 HR/9). While he does not have elite velocity, Keller's fastball graded out as one of the best among regular starters thanks to the pitch's movement. His slider was also above average according to FanGraphs' Pitch Values. If he could create a bigger velocity gap between his fastball and changeup, Keller could be something, but until then he'll be a risky, low-K arm on a bad team.