Japan manager Alberto Zaccheroni has admitted that his team were not brave enough in their World Cup Group C match against Greece.

The Samurai Blue were held to a goalless draw against the Greeks on Thursday evening, despite playing against 10 men for more than 50 minutes of the match.

"Japan should be brave enough to play at the international level by imposing its game on opponents and playing fast," FIFA.com quotes him as saying.

"In the last two games unfortunately we were not able to play with the speed we were accustomed to."

Japan face Colombia in their final group game next Tuesday in Cuiaba.