A former major leaguer playing in the top South Korean league has failed a doping test.

The Lotte Giants in the Korea Baseball Organization announced Thursday outfielder Jim Adduci tested positive for Oxycodone, a synthetic opiate, on May 21. The Korea Anti-Doping Agency administered the test, and the final confirmation is expected Friday.

Starting this year, the KADA is running all doping tests in professional sports, having taken control from respective leagues under the Sport Promotion Act that passed last fall.

Under toughened penalties also introduced with the law, first-time offenders face a 72-game suspension. Second-time violators are to be banned for an entire season.

If Adduci's positive result is confirmed, the one-time Texas Ranger will be the sixth KBO player to flunk a doping test and the third foreign player, after a pair of former big league pitchers, Runelvys Hernandez in 2009 and Ricardo Rodriguez in 2010. Hernandez and Rodriguez were both released by their clubs before their test results were made public.

According to the Giants, Adduci attended a KADA hearing on May 27 and said he'd been taking painkillers, prescribed in the United States, to deal with chronic back problems. He also said he didn't know Oxycodone was a banned substance here because it isn't an anabolic steroid or hormone.

Adduci has endeared himself to South Korean fans with his hard-nosed playing style. In his first KBO season in 2015, Adduci batted .314 with 28 home runs, 106 RBIs and 24 steals, becoming the first Lotte player to enjoy a 20-20 season.

This year, Adduci is batting .291 with seven home runs, 41 RBIs and 15 steals in 64 games.

Through the Giants, Adduci said he takes full responsibility for the result, and he will humbly accept whatever punishment that the KBO metes out. He also apologized to the KBO and its fans for his actions.

The Giants, who removed Adduci from the active roster last Friday, also issued an apology and said they would try to prevent a recurrence of similar cases. (Yonhap)