A little over a year ago, the Mets took left-handed pitcher Sean Gilmartin out of the Minnesota Twins’ organization in the major league phase of the Rule 5 draft. Picked in the first round of the 2011 amateur draft by the Atlanta Braves, Gilmartin was traded to the Twins for Ryan Doumit following the 2013 season.
Things hadn’t gone poorly in his first couple of season in the Braves’ system, but he spent much of the 2013 season in Triple-A and finished the year with a 5.74 ERA at the level. He bounced back in 2014 with a 3.71 ERA overall between his time in Double-A New Britain and Triple-A Rochester. But his numbers were worse in Triple-A again, and the Twins did not protect him ahead of the Rule 5 draft.
A starter in all but one of his 80 minor league appearances, Gilmartin moved to the bullpen upon joining the Mets. As a Rule 5 pick, the team had to keep him on the active roster all season to retain him beyond 2015. Because of that, his inclusion on the Opening Day roster wasn’t surprising—especially after fellow lefty Josh Edgin underwent Tommy John surgery.
Considering the circumstances, things went really well for Gilmartin in his rookie season. In 57.1 innings, he had a 2.67 ERA and 2.75 FIP. He struck out 8.48 opponents per nine and walked 2.83, and he limited home runs to 0.31 per nine. Splits over a sample shouldn’t be weighed too heavily, but Gilmartin fared well against both left- and right-handed batters, with similar peripherals in all of the big categories and a slightly better FIP against lefties. He finished his regular season with a spot start against the Phillies, as the Mets were preparing for the playoffs, and allowed two runs in five innings.
Gilmartin’s 2.58 ERA as a relief pitcher was the same as Craig Kimbrel’s and ranked 41st among 137 qualified relief pitchers in baseball. But of the eleven Mets pitchers who threw at last ten innings out of the bullpen in 2015, Gilmartin was used in the second-lowest leverage situations. Carlos Torres, Alex Torres, and Bobby Parnell—all of whom were less effective—pitched in significantly higher-leverage situations. Perhaps Gilmartin’s numbers would have looked different if he had pitched in those spots instead, but it would have been nice to find out. Keeping with that theme, he made just one postseason appearance when he came into Game 2 of the World Series with the Mets trailing by six in the eighth inning.
Since he stayed with the Mets all season, Gilmartin is now under team control moving forward. He has options remaining, which means the Mets could send him back to the minors if they’d like. Unless the Mets acquire one or more relief pitchers this offseason, though, he looks like he could best serve the team working out of the major league bullpen. And if he must be pressed into service as a starting pitcher, it probably wouldn’t take too long to stretch him out for the job.