Japan's rugby coach John Kirwan has refused to make any knee-jerk reaction after Tongan-born winger Christian Loamanu failed a doping test.
The 22-year-old, a member of Japan's 2007 World Cup squad, tested positive for marijuana and other substances last month, according to his Toshiba Brave Lupus club.
Loamanu has denied taking the drug and asked the Japan Anti-Doping Agency to re-test him.
Kirwan, a former All Blacks great, says it's a concern for Loamanu as a young man but says the player told him he didn't do it so he's happy to wait for the second sample.
Loamanu has been suspended temporarily pending the result of his B sample, meaning he will miss this weekend's domestic league final against Sanyo Wild Knights.
Japan has strict laws on drugs, although even the ancient sport of sumo has been tarnished after several of the wrestling giants were arrested for possession of marijuana.