South Korea Makes Another Change in Classic Series; Fireballer O'Brien Officially Withdraws, Kim Je-yeon Called Up for the 12-Team Tournament

Right-handed pitcher Riley O'Brien from the St. Louis Cardinals is out of the World Baseball Classic team for South Korea because of a calf injury. Kim Je-yeon from the Doosan Bears, who participated in the 12-team tournament, will take his place. The Korea Baseball Organization released this news today.

With under two weeks left before the Classic starts, South Korea has to revise its bullpen setup. The reason is that Korean-American MLB pitcher O'Brien cannot participate due to a calf injury. The KBO confirmed today that 21-year-old right-hander Kim Je-yeon from the Doosan Bears will replace him, and they have applied for official approval of the substitution from the Classic organizers.

O'Brien was originally planned by South Korea’s head coach Ryu Ji-hyun as the closer responsible for the final inning. His fastest pitch exceeds 160 km/h, and last year he was a key bullpen player in the Major Leagues. However, on the 15th during bullpen practice, he felt pain in his right calf and was unable to continue pitching. The Korean team judged that he would not recover in time for the Classic schedule. Ryu Ji-hyun stated, “If O'Brien cannot play, we must revise our strategy and reassess the closer position.”

Kim Je-yeon, who has been called up as a replacement, is a proven pitcher in the KBO League. He recorded 19 saves in 2024 and 24 saves in 2025, and has previously been selected for the 12-team World Baseball Classic squad. Starting tomorrow, the Korean team will play six warm-up games against KBO teams training in Okinawa, where the coaching staff will evaluate new candidates for the closer role.

Injuries have plagued the South Korean team, causing frequent roster changes. Among the 30 players announced on February 6, catcher Choi Jae-hoon, pitchers Moon Dong-joo and Won Dae-in are injured. Meanwhile, Tommy Edman, Kim Ha-seong, and Song Seong-mun from the Major Leagues were already excluded from the roster due to injuries before the announcement.