The Mets signed right-handed pitcher Jim Henderson to a minor league deal in early December as little more than a minor league flier. Henderson had pitched only 11.1 major league innings in the past two years, undergoing shoulder surgery in 2014 and spending 2015 posting poor results in the minors. Still, he owns a career 12.09 K/9 and 3.21 FIP, and he registered 28 saves in his last healthy season. That sort of performance is almost always worth a gamble in the offseason.
So far, Henderson has made good on that flier. In 6.2 spring innings, he's allowed only one run and struck out nine while walking none. Spring numbers should always be taken with a heavy grain of salt, but the scouting reports match Henderson's results. His fastball is touching 95 and sitting in the 92-94 mile per hour range—not quite the velocity he had pre-surgery, but more than enough to be effective. Henderson's plus slider has also returned, showing the sharp break that made him such an effective closer for the Brewers.
During his brief peak in Milwaukee, Henderson excelled at generating strikeouts but struggled with walks and, at times, home runs. A reliever can get away with a BB/9 in the high-3s when they're striking out nearly a third of batters, but it greatly limits their wiggle room. Henderson doesn't have a particularly good batted ball profile to fall back on either, as he induces few ground balls and gives up plenty of line drives and hard contact—the second highest and sixth highest rates respectively among relievers in 2013. Plenty of good relievers can survive with these flaws, but it emphasize how important strikeouts are to Henderson—if he's not generating them at a well above average rate, he's a liability on the mound.
We're not far removed from years when a minor league flier like Henderson would be expected to serve an important late inning bullpen role. The Mets have much better bullpen depth these days, and Henderson won't be expected to serve more than a middle relief role barring a couple injuries. With his strong spring performance, contractual status, and Terry Collins's penchant for leaning on veterans, Henderson seems likely to make the club as a fourth right-handed reliever. If he can come close to his previous levels of success, the Mets will turn a big profit on their minor league gamble.