Through three major league seasons, Jonathan Stanley Loaisiga’s solidified himself as a middle-tier reliever capable of eating multiple innings on command, but without the kind of strikeout stuff teams look for in their most trusted firemen. While his ERA has dropped a full run-and-a-half between his first and third seasons, his xERA has remained steady; all three seasons’ marks have held within two-tenths of a run of each other. So far, he’s been serviceable, but not much more than that.
This spring, however, Loaisiga looks like a man on a mission to transcend his current station in the Yankees’ pitching pecking order. Through 13.1 innings, he’s allowed just two runs to scratch while maintaining a WHIP of 0.60, holding opponents to a batting average of just .133. While of course, spring training stats must be taken with a couple grains of salt, given the lesser competition in terms of play and spirit, Loaisiga’s total dominance has been noteworthy nonetheless.
While Loaisiga’s original slot in the Yankees’ staff was in the 2018 starting rotation, replacing a then-injured Jordan Montgomery, he relied almost exclusively on a fastball and curveball. With such a limited arsenal, Loaisiga struggled in his second trip through a batting order despite carving batters the first time around. In 2018, opponents posted an OPS of just .500 in their first trip to the plate, but that number ballooned to .852 in their second turn through.
To mitigate the limitations of Loaisiga’s short supply of plus-pitches, the Yankees opted to refrain from allowing him to face batters a second time nearly as often. In 2018, 37.0% of Loaisaga’s opponents’ plate appearances came after they’d already faced him once, whereas that number fell to just 20.9% and then 11.0% of the time in the following two seasons.
In 2020, Loaisiga struggled to make the most of his stellar stuff by failing to generate the kinds of swings and misses that separate a good reliever from a great one. His elite fastball velocity, fastball spin, and curve spin helped him limit opposing batters to an average exit velocity in the game’s 95th percentile, but he finished well below average in terms of K% and Whiff% compared to his peers.
Since he throws a four-seamer or a sinker more than two-thirds of the time, batters rarely get blown away by his fastball, spitting on curveballs lest he was to completely hang one. While it doesn’t move as sharply as his curve, Loaisiga could be served by leaning a bit harder on his changeup. Loaisiga’s fastball has grown more effective as he’s democratized his pitch mix over the past couple of seasons, so in this case, less actually may be more. If he can use his most powerful weapon more sparingly, and locate it around the top of the zone instead of at belt-height, he might be able to get more swings and misses on the pitch, turning soft contact into strikeouts and improving his overall effectiveness.
This spring, he’s done just that, although it hasn’t yet boosted his ability to send batters back to the dugout on strikes. Even with his strong overall numbers, Loaisiga has still struggled to strike batters out, posting just a 6.91 K/9, significantly worse than his career average of 10.4 K/9. While Loaisiga’s maintained stellar whiff rates with his two offspeed pitches he’s been unable to generate nearly any swings and misses with his fastball, despite the pitch’s above average velocity, spin, and rise.
The fact that he’s thrown fewer fastballs this spring is a good sign towards his development as a pitcher, and the strikeouts may begin to come as he gets more comfortable throwing his offspeed pitches in more counts. However, he’ll never be a truly great relief arm unless he makes good on this qualitative, marginal progress. Should he start to generate whiffs the way Chad Green and Aroldis Chapman do, Loaisiga will find himself working his way up the bullpen pecking order. Failing that, he may continue to slot in as a nice middle relief arm.