Seattle Mariners first baseman Choi Ji-Man was suspended for 50 games without pay by Major League Baseball on Thursday after testing positive for a banned performance-enhancing substance.
The 22-year-old South Korean was found to have the steroid methandienone in his system during a drug test, triggering an immediate ban.
Choi was added to the Mariners' 40-man roster in November but has started this season with Seattle's top developmental club, the Tacoma Rainiers, based near the Mariners in Washington state.
In 10 games this season, Incheon-born Choi batted .394 with one home run and five runs batted in while walking seven times and striking out six in 33 plate appearances.
The Mariners fell to 7-8 this season with an 8-6 loss Thursday at Texas, their third loss in a row to the Rangers. Seattle is level for third place with the Los Angeles Angels in the American League West division.