Ko Woo-suk's suspension cut from 10 games to 8 in foreign substance case

Ko Woo-suk, a pitcher in the Minnesota Twins organization, has had his suspension reduced from 10 games to 8 after facing allegations that he used a foreign substance on his glove during a Triple-A game.

Rico Sports Agency, which represents Ko, announced Monday that MLB had reduced the 28-year-old's suspension following an appeal. With the penalty finalized at 8 games, Ko can return to the field as early as Wednesday.

The incident occurred July 24 (local time) at CHS Field in St. Paul, Minnesota, during a Triple-A game between Ko's Saint Paul Saints and the Columbus Clippers. Umpires inspected Ko's glove as he prepared to take the mound in the seventh inning.

The inspection found a substance on the webbing of the glove, and Ko was ejected immediately without throwing a single pitch. MLB subsequently handed down a 10-game suspension.

Foreign substances on a pitcher's glove are prohibited because they can affect the spin and movement of the ball, constituting illegal pitching.

After the suspension was announced, Ko took to social media to deny any wrongdoing. "The substance on my glove was not intentionally applied — it formed naturally as sweat and rosin hardened," he said. "I have used that glove in every game since the 2023 World Baseball Classic, and not once has it been flagged as a problem."

Ko added that the material in question was so hardened it could barely be scraped off even with a fingernail. "It could not be removed, and there was no reason to remove it," he said. "I am confident it had no effect whatsoever on my pitching."

Ko filed an appeal through the players' union, and the suspension was ultimately reduced by two games to 8. MLB did not disclose the grounds for the reduction, but the outcome is widely interpreted as a partial acceptance of Ko's arguments.

Ko joined the Twins' major league roster July 8 after working through the minors since arriving in the US in 2024, and made his big-league debut against Cleveland on July 10. He was optioned back to the minors after giving up three runs in one inning against Cleveland on July 21, and carries a career MLB line of 1 hold and a 9.00 ERA over 4 appearances.