Mariners prospect Ji-Man Choi was suspended for 50 games on Thursday after testing positive for a performance-enhancing substance.
Choi, 22, denied using a banned substance but said he would not appeal the suspension.
The Office of the Commissioner of Baseball indicated that the first baseman received the 50-game ban without pay after testing positive for methandienone, a performance-enhancing substance. Since Choi is on the Mariners' 40-man roster, the suspension is considered a violation of Major League Baseball's Joint Drug Prevention and Treatment Program, not the Minor League program. MLB said the suspension is effective immediately.
"A banned substance was detected in my urine sample," Choi said in a statement, according to The Tacoma News Tribune. "I do not know what I could have taken that caused me to test positive. I have not and never would knowingly use anything illegal to enhance my performance. However, I also understand that without an explanation I must serve a suspension and I accept that. I look forward to putting this behind me and to returning to help the Mariners ballclub once my suspension has ended."
Choi, who was named the Mariners' No. 20 prospect by MLB.com earlier on Thursday, is batting .394 with a homer, five RBIs and a .500 on-base percentage in 10 Pacific Coast League games this year. The native of South Korea posted solid numbers at three levels in 2013, batting .295 with career highs in homers (18), RBIs (85) and walks (63).
"The Seattle Mariners are disappointed to learn of today's suspension of [Triple-A] infielder Ji-Man Choi," the Mariners said in a statement. "The organization fully supports Major League Baseball's Joint Drug Prevention and Treatment Program and its efforts to eliminate performance-enhancing substances from our game. Per the Basic Agreement, the Mariners will have no further comment."
Methandienone, sometimes known as "d-bol," is an anabolic steroid that can help increase protein synthesis and muscle strength, which reportedly makes it popular among some bodybuilders. Side effects may include high blood pressure. Braves Minor League catcher Orrin Sears also tested positive for the substance on Feb. 14.
Choi, 23, signed with the Mariners as a free agent in 2009 and was a Futures Game All-Star last year. He was the Arizona League MVP in 2010, was voted a California League All-Stat in 2013 and was named an MiLB.com Organization All-Star this past offseason.
The Commissioner's Office has suspended 20 players this season for violating the Minor League Drug Prevention and Treatment Program, although Choi's suspension falls under the Major League Joint Drug Prevention and Treatment Program. The positive test is in effect prior to the recent changes to the program that were jointly announced by Major League Baseball and the Major League Baseball Players Association on March 28.