Go, 25, was just posted after seven seasons in the KBO, with the past five serving as the LG Twins' closer. He posted a 3.68 ERA in 44 innings last year but has a 2.17 ERA and 1.48 ERA during the 2021 and 2022 seasons.
Go throws a fastball in the mid to upper 90s and offers a cutter, slider, and curveball as his secondary pitches. Go posted a career-best 12.1 SO/9 in 2023, something that the Cardinals would to add to the back of their bullpen.
The Cardinals have had success diving into the Korean market for relief pitchers in recent years, with names like Seung-hwan Oh and Kwang-hyun Kim carving out significant roles for St. Louis. While it's unclear what kind of contract Go will be seeking in free agency, I can't imagine it would be a significant number among relievers, as he's unproven at the big league level and did not have much of a following entering the offseason.
John Mozeliak has noted the Cardinals' work to build a strong reputation and scouting presence throughout Asia, making the link to the Cardinals here make all of the sense in the world. St. Louis should be one of the more forefront clubs when it comes to these lesser-known players from Korea, and they could once again capitalize in the case of Go.
With the Cardinals wanting to add multiple arms to their bullpen while also remaining opportunistic in adding another front-line stater, it would make sense to go after some arms with great stuff but are relatively unknown. At just 25 years old as well, Go should be in the prime of his career and could look to continue to improve his strikeout stuff like he has done year after year in the KBO.
Some other relievers have been linked to the Cardinals in recent weeks, including Phil Maton and Jordan Hicks. It sounds like the club really wants to add another high-leverage right-handed reliever, but with a lack of depth from the left side as well, they could look to add one or more of each.