Mariners miss out on free agent target Hye-seong Kim as slow off-season continues

Kim wasn’t the answer to the Mariners’ holes in the infield, but he was an answer.

Today was the deadline for KBO infielder Hye-seong Kim, formerly of the Kiwoom Heroes, to sign with a team. Though many predicted the infielder would sign with the Mariners, news broke today he has opted to sign with the Dodgers instead:

Reportedly, the deal is for three years and $12.5M, with options that could extend it to five years and $22M. Kim had a deadline to sign with a team by January 3rd following the conclusion of his 30-day posting period; he traveled to the US during that time before returning to Korea to work on the 500+ hours of community service he’ll need to complete in exchange for an exemption from active duty in South Korea’s military. To acquire Kim, the Dodgers will pay the Heroes his posting fee (20% of his contract), plus any additional supplemental fees.

Kim was an attractive target for the Mariners, who had a vacancy at second base, the position he played in the KBO at an All-Star level. While the KBO doesn’t award Gold Gloves same as MLB but rather as like a positional “MVP” award, combining offensive and defensive performances, for each position, Kim has won the second base award each of the past two years. While second is his natural home, his speed can help him slot into the outfield, and he can also play third base and shortstop; he’s the only player in KBO history to have won the positional award at both second base and short. Two years ago, KBO also created a defense-only award for each position; Kim won that as well in each of the first two years of the award for second base.

The other standout skill in Kim’s toolkit is his speed; in seven seasons in the KBO, he’s swiped 25+ bases in six of them. His 211 steals are the most in the KBO since 2018.

But what really made Kim seem like a good fit for the Mariners is his aversion to striking out—like, think borderline single-digits. Even if his strikeout rate from 2024 were to double facing MLB pitching, he’d still strike out more than only two other Mariners regulars in 2024 (Justin Turner and Victor Robles). Even given the steepest of learning curves in moving stateside, he’d provide consistent contact for a lineup that seemed downright allergic to it at times last season.

The question is the quality of that contact. Kim’s big lefty swing, while quick, has a steep uphill plane and could be exploited by MLB’s power pitchers. If you want to see more, there’s a lengthy highlight reel here of his hits, a number of which, to my eyes at least, would turn into outs in MLB with better outfield play/defensive positioning.

His career-high in home runs is 11, a mark he achieved this year in his age-25 season. For comparison, his former KBO teammate and former Padres shortstop Ha-Seong Kim, who has been roughly a league-average player since coming over three years prior, hit about double Hye-Seong’s high water mark of 22 homers each year he was in the KBO. For the lighter-hitting Hye-Seong’s skillset to work in MLB, he has to be able to hit enough to get on base, where his plus speed makes him a threat, and there’s no guarantee that will happen.

While Mariners fans are justifiably frustrated with the lack of activity this off-season, it’s unlikely that Hye-seong Kim, in his first year stateside, would move the needle significantly considering the Mariners’ offensive struggles last year. It is surprising to see Kim select a platoon role with the Dodgers rather than an everyday role with the Mariners, but a more limited role on a powerhouse team could ease his transition into MLB, while the structure of the contract allows both sides to make adjustments based on how he adjusts to the league—and vice-versa. But it’s undeniably disappointing for Mariners fans eager to see something, anything to get excited about for next season, and as much of a question mark as Kim is, signing him undeniably would have both injected new energy into the fanbase, and also assuaged Mariners’ fans concerns that the team is an afterthought, or worse, an undesirable place to be, in the minds of free agents. Instead, a long, slow off-season plods on.