Hajime Moriyasu has already led Japan to qualification for next year's World Cup finals but there was no disguising his frustration at his understrength side losing 1-0 to Australia in Perth on Thursday.
Aziz Behich's 90th minute strike consigned the Samurai Blue to a first loss to Australia in 16 years and a first defeat in all matches since February last year.
"It ended up being an extremely frustrating and disappointing result," Moriyasu told reporters.
"Many inexperienced players were in action, but they were enthusiastic in practice, showed their best, and were prepared to fight like Japan as a team."
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