Why the Cubs Should Sign Free-Agent Infielder Sung Mun Song

[Paul Niemiec]

Image courtesy of MLB.com

The Kiwoom Heroes of the Korean Baseball Organization have posted their star third baseman, Sung Mun Song. He now has until December 21 to sign with an MLB club. If he doesn't, he will return to the Heroes for 2026, but it looks as though Song will join the slow but steady stream of Korean hitters coming to the United States in their prime. The 29-year-old is coming off a season wherein he hit .315 with a .917 OPS in 144 games. He hit a career-high 26 home runs and stole 25 bags which was also his best mark yet. He had an equally impressive 2024, in which he hit .340 and led the Heroes in RBIs (with 104) and home runs (with 19).

The left-handed hitter is a bit of a late bloomer. His first excellent season was that 2024 campaign, nine years after he made his debut as a teenager in 2015. He's looking to join former teammates Ha-Seong Kim, Jung Hoo Lee, and Hyeseong Kim in the American majors. He's two years the latter two players' senior, but a year younger than Ha-Seong Kim.

Song has some serious power and speed, but his offensive game as a whole remains in question. He offers some defensive versatility, as he has played first and second base in addition to his primary spot at the hot corner, and will likely be viewed as a potential bench option in the majors. This is a player who likely won’t be chased by the first class contenders. If Song chases playing time instead of a ring, he might find what he is looking for with teams like the Angels, Athletics, White Sox, or Marlins.

There have not been any credible rumors on the Cubs’ interest in Song, but they make sense as a possible suitor. Song likely would not hop over Matt Shaw as the starting third baseman on the depth chart, but if Shaw does struggle early on, Song would make for an interesting contingency plan. That he bats lefty also suggests some matchup value; he could spell Shaw against some right-handed starters and strengthen the position for the team by creating a semi-platoon.

The only other reserve infielders on the 40-man roster right now are prospects James Triantos and Pedro Ramirez, so the Cubs do need to add an infielder or two. They signed veteran utility man Scott Kingery to a minor-league deal Tuesday, but Kingery is unlikely to play a significant role for any big-league team, in 2026 or any season thereafter.

In 2025, Shaw was handed the starting third base job with no real competition. This is not a slight to Jon Berti, Gage Workman, Vidal Bruján or 41-year-old Justin Turner, but we saw all regular season and playoffs how unprepared the Cubs were for any potential growing pains with Shaw. Compared with signing an unexciting backup infield option, Song provides more upside. He was one of the best hitters in the KBO in each of the last two seasons, and would add a fun extra storyline in 2026. Early last season, we saw Lee take at least a brief turn one of the best hitters in baseball. If Song produces a well-timed, scorching-hot month or so, that would go a long way toward improving a lineup that is likely to lose Kyle Tucker—and he should come at a very affordable price.

View full article

[Bertz]

I actually like this idea a lot.  Eric Longenhagen's scouting report makes it sound like he's a hell of a defender, strong baserunner, and has good raw power.  So even if the hit tool takes a major beating on the trip across the pacific that's a guy that can help you win in a lot of different ways.  I'd be terrified to hand him a starting job, but to nip at Matt Shaw's heels and provide some insurance if a middle infielder gets hurt?  Hell yeah.

I do think ideally a Song signing would come with a trade, as there are only so many at bats to go around.  Right now on the position player side we are looking at:

- The 8 returning everyday hitters from last year

- Amaya as the backup C

- A TBD veteran right handed bat (there has not been a lot of clarity on what they're looking for beyond handedness)

- Three of the Caissie/Ballesteros/Alcantara/Long quartet

Song would likely take one of those three slots earmarked for the kids.  That's not necessarily a problem, his skillset doesn't overlap any of there's all that much.  But I don’t like the idea of two of the kids having to be banished to Iowa at all times.  So if e.g. Caissie gets dealt for a SP and the teams adds Song, great!  If the team adds Song and now Caissie's got to continue away toiling at Iowa despite OPSing .950 I'm going to scream.