"Ultimately we brought Oh in to what we feel is already a very dynamic bullpen and he will most definitely add to that," Mozeliak told reporters.
Oh, nicknamed the "Final Boss," had a 2.73 ERA, 41 saves and struck out 66 batters in 69.1 innings last season for the Hanshin Tigers. In a career spent in both the Korea Baseball Organization and Japan’s Central League, he's posted a 1.81 ERA and has struck out 10.7 batters per nine innings.
He was so dominant over the last two seasons in Japan that Jeff Passan of Yahoo Sports described him as "the Mariano Rivera of Korea." According to Derrick Goold of the St. Louis Post-Dispatch, Oh "has a fastball that he throws from 93 mph to 95 mph, and he offsets that with a hard slider and a slower breaking ball."
He's made his mark as a closer, though he'll serve as the setup man in St. Louis, with Trevor Rosenthal—who had 48 saves in 2015—entrenched in the ninth-inning role. The move could prove to be a particularly sly one for St. Louis, which missed out on the big free agents this winter but may have given itself the best late-innings duo in the National League with this signing.