Since Jesse Hahn's MLB debut, he has shown the ability to dominate even the most powerful lineups. However, he has never been able to stay healthy long enough to maximize his full potential.
Hahn’s 2015 season came to a screeching halt when he was officially shut down towards the end of the summer with elbow and forearm issues. Before that, he went 8-8 in 23 starts with a 3.35 ERA and a 1.17 WHIP. His K/9 decreased from 8.59 to with the San Diego Padres to 5.96 with the Oakland Athletics. A statistical drop-off is natural when National League pitcher moves to the American League, but such a drastic drop in strikeouts is concerning. We saw an increase in his fastball velocity from 2014 to 2015 (90.5mph to 91.9mph for his two-seamer), but batters were able to make more contact on his fastball. Coupled with a less effective curveball, the drop in K/9 is not much of a surprise.
The potential is there, but the injury history is looming. We can file Jesse Hahn under the “high-risk, high-reward” category in the late rounds.