Posted KBO star Song Sung-mun travels to US with MLB signing deadline nearing

Kiwoom Heroes third baseman Song Sung-mun speaks after winning the Golden Glove award during the ceremony at Lotte Hotel World in Seoul on Dec. 9, 2025. Yonhap

South Korean baseball All-Star Song Sung-mun left for the United States on Friday apparently to finalize a deal with a major league club.

The Kiwoom Heroes, Song's Korea Baseball Organization (KBO) club, said their third baseman departed for America on Friday. Some reports claimed that Song was on the verge of signing a deal with the San Diego Padres, though the Heroes said they couldn't confirm his destination.

Song was posted for Major League Baseball (MLB) clubs in November, meaning any of the 30 clubs in the big leagues would be able to sign him during a 30-day negotiating period. That window closes at 5 p.m. Eastern time on Sunday, or 7 a.m. Monday in South Korea.

If Song lands a deal, he will be the sixth Heroes player to reach MLB, following Kang Jung-ho (Pittsburgh Pirates), Park Byung-ho (Minnesota Twins), Kim Ha-seong (San Diego Padres), Lee Jung-hoo (San Francisco Giants) and Kim Hye-seong (Los Angeles Dodgers).

Song is a client of ISE Baseball, the same U.S. agency that sent Kim Ha-seong to the Padres when it represented him prior to the 2021 season.

Song, 29, is a late bloomer who made his KBO debut in 2015 but had his first breakout campaign in 2024, when he batted .340/.409/.518 and set career highs with 19 homers, 104 RBIs and 21 steals.

This year, Song overcame a slow start to finish with a .315/.387/.530 line, 26 home runs, 90 RBIs and 25 steals.

He earned his first Golden Glove award at third base as the best overall player at his position and also picked up his first KBO Fielding Award at the hot corner. He ranked second in the KBO with 6.84 wins above replacement.

Song, who bats left and throws right, is primarily a third baseman, but has also spent time at second base and first base. He also played shortstop in high school and has said he could handle shortstop duties if asked in MLB.

KBO clubs receive a "release fee" if they lose a player to MLB through posting, and the amount will depend on the guaranteed portion of the player's contract.

The release fee is 20 percent of the first US$25 million and 17.5 percent of the amount exceeding the next $25 million. For instance, if a player signs for over $50 million, then his former KBO team will receive 20 percent of the first $25 million ($5 million) and 17.5 percent of the next $25 million ($4,375,000), plus 15 percent of the amount exceeding $50 million.

If Song cannot come to an agreement with an MLB team by this weekend, he may not be posted again until Nov. 1, 2026.

In August, Song signed a six-year extension with the Heroes at 12 billion won ($8.15 million). It will kick in at the start of the new season if Song doesn't move to MLB and ends up back with the Heroes. But if he does leave, the deal will be automatically voided.