Oh, 35, is a righthander who spent almost decade pitching for Samsung in the KBO, then spent two years pitching for Hanshin in the Japanese League before coming to the United States after the 2015 season. Oh spent the 2016 and 2017 seasons with the St. Louis Cardinals, finishing 6th in the N.L. Rookie of the Year balloting in 2016 after putting up a 1.96 ERA in 79.2 IP, before regressing in 2017, allowing a 4.10 ERA in 59.1 IP.
Oh’s struggles in 2017 were due to his K rate dropping significantly (from 11.6 K/9 to 8.2 K/9), while allowing twice as many home runs as he did in 2016. While Oh was dominant against both lefthanders and righthanders in 2016, he allowed lefthanded hitters to put up a 1006 OPS against him in 2017, compared to a 642 OPS against righthanders. Oh is mostly a fastball/slider pitcher, averaging about 93 mph on his fastball last year, while also mixing in an occasional split-finger pitch.
No word yet on whether this is a major league deal or a minor league deal, though were I to guess, I’d pick major league deal. Oh joins Tony Barnette and Chris Martin as former Japanese League relievers in the bullpen for 2018, and with that trio, Keone Kela, Matt Bush, Jake Diekman and Alex Claudio, it would appear the bullpen is close to being set.
UPDATE -- Robert Murray of Fan Rag Sports says it is a one year, $2.75 million deal with a $4.5 million club option in 2019 and a $250,000 buyout, with a possible $1 million in incentives each year. The Rangers will have to clear a spot on the 40 man roster for Oh, though if they wait another week or so until spring training starts to make it official, they could move Joe Palumbo to the 60 day disabled list to create room on the 40 man for Oh.