Hirano (who turns 37 in March) rose to prominence over 11 seasons with the Buffaloes from 2006-17, posting a 3.10 ERA, 22.09 strikeout percentage, and 5.7 walk percentage over 974 2/3 innings. After transitioning into relief pitching in 2009, Hirano became one of NPB’s top closers, racking up 156 saves during his previous stint in a Buffaloes uniform.
Hirano came to North America after signing a two-year, $6MM deal with the Diamondbacks in the 2017-18 offseason. The transition was initially smooth, as Hirano posted a 2.44 ERA over 66 1/3 innings out of Arizona’s bullpen and finished sixth in NL Rookie Of The Year voting in 2018. Some elbow problems hampered Hirano in 2019, however, and after signing a free agent deal with the Mariners last winter, his arrival to Seattle’s Summer Camp was delayed by a positive COVID-19 diagnosis.
All told, Hirano delivered a 3.69 ERA over 131 2/3 innings in the Show — not bad results for a pitcher who lacked a big fastball, and posted only a middle-of-the pack 23.5K% and 14K-BB%. Hirano induced a lot of soft contact from hitters and had a 47.3% grounder rate over his MLB career, though home runs became an increasingly larger issue for the righty.