Australia rugby league international Blake Ferguson said on Monday he could “hardly stand up” after a month in a Japanese prison and would plead guilty to drug charges that derailed his career.

Ferguson was arrested over an alleged assault and possession of illegal drugs in Tokyo last month as he prepared to make his rugby union debut with top-flight club NEC Green Rockets Tokatsu.

Instead, he was thrown in jail and his contract, reportedly worth Aus$1.5 million (US$1.1m), was torn up.

The 31-year-old is now free but remains in Japan awaiting a court appearance in March.

“I’m going to plead guilty and hopefully they will show some leniency. It’s important that I accept responsibility,” he told the Sydney Daily Telegraph.

“I got myself into this mess and there’s no one else to blame.”

Ferguson, who played more than 200 games for a host of Australian clubs and appeared seven times for the national team, said being jailed was “lonely and boring”, with his phone confiscated and no contact with his family.

“It was just me and some Japanese guys who couldn’t speak English. I read a few books but that was about it. The food was pretty ordinary and I got a really bad back,” said the father of three.

“Seriously, the mattress would have been a centimetre thick. I could hardly stand up for a few days. I certainly wouldn’t want to go back.”

His agent, Sam Ayoub, told the newspaper it was too early to say whether Ferguson would play rugby again.

“I don’t know what interest is out there because we haven’t gone to the clubs,” he said. “Our priority is to get Blake home to his family and then take it from there.”

© Agence France-Presse

Photo: Darrin Klimek