Sung-mun Song Adds Newfound Stability, Versatility to Padres' Infield

A.J. Preller has been activated. As evidenced by the San Diego Padres' re-signing of Michael King and signing of South Korean infielder Sung Mun Song, the organization now stands to play a significant role in how the remainder of the winter transpires across the landscape of Major League Baseball. And while the addition of Song, in particular, could have a bearing on the team's willingness to deal from their position player group, he stands to serve as a wildly important addition regardless of how the rest of the offseason unfolds.

The 2025 Padres lacked infield depth. Outside of the starters, it was a group that was led by Jose Iglesias in a reserve role. The veteran appeared at second base for 40 games, third base for 24, and shortstop for another 32. Mason McCoy made a dozen appearances at short and another two at the keystone. There was a smattering of Tyler Wade in there early, too. To recap, that's a wRC+ of 73 (Iglesias), 42 (McCoy), and 69 (Wade) in support of their starting group. And that starting group didn't remain healthy throughout the year, with Xander Bogaerts, in particular, only appearing in 125 games. Plus, Jake Cronenworth missed a bit of time early in the year. Suffice it to say that when there was an absence — however brief it may have been — the Padres had a problem on their hands without any supplemental offense to speak of. Song's addition changes the calculus entirely. 

In general, the team is getting a versatile infielder that supplements the starting lineup with significantly more offensive upside than anyone they trotted out last year. His most recent KBO action featured a .315/.387/.530 line with 26 homers and 25 steals. Song logged time only at second and third base last year but also has some first base reps to his credit. His addition, as such, unlocks some versatility for the current roster. 

As things stand right now, you're looking at some combination of Gavin Sheets and Luis Campusano at first base. Jake Cronenworth will primarily handle the keystone while bouncing over to first occasionally. Xander Bogaerts and Manny Machado remain in place to handle shortstop and third base, respectively. While first base still stands as the most likely of the positions for an upgrade at present (barring a trade of Cronenworth), let's momentarily assume that no further transactions unfold with respect to the infield.

Sheets' on-paper ability to move to the outfield corners and Campusano's current obligation as the team's No. 2 catcher allows new manager Craig Stammen to work Song in with some frequency, perhaps even as the primary first baseman if he's more content to have Sheets serve as a DH and let Campusano develop his glove behind the plate without additional obligations. Cronenworth can also slide over if he wants Song in at second base.

Perhaps most importantly, though, is the fact that Song can step in reliably at third. That allows Stammen to work Machado in as the designated hitter with at least a little more frequency. We've seen his bat go through questionable stretches and his glove work decline a shade over the last two years. The flexibility there just adds a bit more of a safety net in those stretches where an approach or mechanical adjustment is needed on the part of Machado, without the extra burden of focusing on the defensive side of the ball. It's not that Song will supplant Machado for any meaningful stretch of time, but more so that he just offers that extra layer of protection for an essential player entering a season in which he'll turn 34 years old. 

Regardless of specifics, though, it cannot be overstated how much more dynamic the infield group becomes with Sung-mun Song now in the mix. Even if he's unable to attain a role as a traditional everyday player, he offers a level of offensive upside as a fill-in or injury replacement that the Padres lacked entirely in 2025. Not only does he offer the bat-to-ball skills that you prefer from that kind of role, but he possesses much more power and speed upside. While it's now much more likely that they deal from this group than it might have been even a few days ago, it's clear that the floor has been raised considerably on the infield grass in San Diego.