Seunghwan Oh’s option for the 2019 season already vested when he appeared in his 70th game of the season, but the Rockies right-hander told reporters in his native South Korea on Wednesday that he is considering a return to the Korea Baseball Organization (link via Jee-ho Yoo of the Yonhap News Agency).

“I am a bit exhausted after spending five seasons in Japan and the United States,” said Oh, who pitched for Japan’s Hanshin Tigers in 2014-15, the St. Louis Cardinals in 2016-17 and the Blue Jays and Rockies in 2018. “I feel like I want to return to the KBO while I still have the energy to help the team and pitch in front of home fans. I can’t make this decision alone. I’ll have to speak with my agency about the next season.”

It’s a surprising development for a player who is already under contract at a $2.5MM rate that is modest in the United States but would be a substantial salary in the KBO. Then again, the 36-year-old Oh was the KBO’s premier reliever for nine seasons (2005-13) and has had plenty of success in five years pitching between NPB and MLB, so his career earnings are already substantial. Money likely isn’t the primary motivating factor for him at this point. To that end, Oh acknowledged: “It’s not easy living in a foreign country. … Everything away from the stadium is an extension of competition.”

It’s not clear exactly how a move back to the KBO would come together. Yoo notes that Oh’s former club, the Samsung Lions, still controls his rights in the Korean league, though he quotes a Lions official indicating that he was not aware of Oh’s desire to return until learning of it through the media. That executive, though, said the Lions could “explore different possibilities” with Oh should he pursue a return to South Korea. Oh would also be facing a 72-game suspension after the Korean courts fined him for gambling in a foreign casino (a violation of South Korea’s strict gambling laws), which will likely factor into his decision process.

If Oh does ultimately head back to the KBO, it’d be an unexpected blow for a Rockies club that surrendered a pair of prospects — Forrest Wall and Chad Spanberger — when acquiring his services from the Blue Jays back in a late July trade. Presumably, the Rockies and Oh would come to an agreement that would void the remainder of his contract (as was the case with the Twins and ByungHo Park when he, too, decided to return to Korea), though perhaps some additional financial determinations (e.g. compensation from the Lions) would need to be discussed.

Oh was outstanding both in Toronto and Denver this season, pitching to a combined 2.63 ERA with 10.4 K/9, 2.2 BB/9 and 1.1 HR/9 in 68 1/3 innings of work. That strong bounceback season netted him $500K worth of incentives on top of his $1.75MM base salary and made his 2019 option look to be a considerable bargain for a Rockies bullpen that saw high-priced offseason acquisitions Bryan Shaw and Jake McGee both flounder in the first season of matching three-year, $27MM pacts. Beyond that, Colorado is also slated to lose standout late-inning reliever Adam Ottavino to free agency, making the potential loss of Oh an even greater problem.