KBO’s Kiwoom Heroes Post Infielder Sung-mun Song

The Kiwoom Heroes of the Korea Baseball Organization have agreed to post infielder Sung-mun Song, reports Jeeho Yoo of Yonhap News. The KBO posting window is 30 days (unlike the 45-day period for players coming over from Japan’s NPB). MLB teams will officially be able to negotiate with Song, whom Yoo adds has hired ISE Baseball to represent him, on Saturday morning. He’ll need to sign by 5:00 pm Eastern on December 21 or remain with the Heroes.

Song, 29, is a left-handed hitter who has played all nine seasons of his career with that club. He posted a sub-.700 OPS every year between 2021-23 but has taken a leap forward at the plate over the past two years. Song hit .340/.409/.518 last year and is coming off an equally impressive ’25 campaign. He popped a career-best 26 home runs with a .315/.387/.530 slash across 646 plate appearances.

Among 30 KBO hitters with 500+ trips to the dish, Song finished sixth in both average and on-base percentage and was third in slugging. He also finished third in home runs (albeit well behind former MLB first baseman Lewin Díaz’s league-best 50 longballs). Song walked at a 10.5% rate while striking out 14.9% of the time. The strikeout rate would be excellent against big league pitching but is only a little better than average in Korea, where the velocity is lower and hitters put far more balls in play.

Eric Longenhagen of FanGraphs gave Song a 45 FV grade, which is commensurate with a mid-level prospect from the typical organization’s top 30 list. Longenhagen credited him with plus power to the pull side and a plus arm at third base, where he has spent most of his KBO career. He’s a good athlete who stole 25 bases this year and has gone 46-48 in stolen base attempts over the past two seasons.

The biggest question is his pure hitting ability. Longenhagen writes that Song has shown a bit of a propensity to chase outside the strike zone and has an uphill swing path that can leave him vulnerable to pitches up in the zone, especially those on the outer half. Readers are encouraged to check out FanGraphs’ full scouting report for more details. Will Sammon and Cody Stavenhagen of The Athletic wrote earlier this month that evaluators with whom they spoke viewed Song more as a utility player than a regular.

Song has some defensive flexibility, but an inability to play shortstop limits his value as a utility piece. He’s primarily a corner infielder who also has almost 1300 innings at second base. The Angels need a third baseman and are looking for a left-handed bat to balance a righty-heavy lineup. The Astros also want to bring in a lefty-hitting infielder, though they’d need to feel comfortable playing Song regularly at second base unless they trade one of Isaac Paredes or Christian Walker. The A’s are in the second and third base markets, while the Mariners could be as well depending on whether they re-sign their own free agents. The White Sox, Pirates, Marlins, Rangers, Diamondbacks, Tigers and Royals (with Maikel Garcia capable of playing second) could all be in the mix for a third baseman.

A signing team would owe a posting fee to the Heroes on top of whatever is guaranteed to Song. That’s proportional to the contract value: 20% of the first $25MM, 17.5% of the next $25MM, and 15% thereafter. It’d be surprising if Song tops $25MM, so the likeliest outcome is that the release fee will be 20% of the guarantee.

Song is the only KBO player known to be on the posting radar this offseason. First baseman Baek-Ho Kang was reportedly considering an MLB move, but he signed a four-year contract with the KBO’s Hanwha Eagles this week. While Cody Ponce is expected to return to MLB after a dominant KBO season, he’ll do so as a free agent rather than via the posting system. There are three much higher-profile NPB players making the jump via the posting system: Tatsuya Imai, Munetaka Murakami and Kazuma Okamoto. Japanese righty Kona Takahashi is also being posted but will command a far lower contract than the other three.