Sanfrecce Hiroshima defender Kazuhiko Chiba has been tentatively banned from playing due to a positive test for doping, the reigning J. League champions announced on Thursday.

The 31-year-old Chiba tested positive for methylhexanamine, an energy-boosting stimulant that is banned by the World Anti-Doping Agency.

The test was carried out by the Japan Anti-Doping Agency (JADA) after Chiba played in Hiroshima's league game against the Urawa Reds on Sept. 25.

According to Hiroshima, Chiba did not knowingly take the substance, which was found in one of two urine samples he submitted. Hiroshima said it has asked JADA for a test of the other sample along with a hearing to clarify the facts.

For the time being, Chiba will be banned from playing in official matches and participating in team practices.