Okada is believed to be wary that Verbeek, a former coach of J.League clubs Omiya Ardija and Kyoto Sanga, may use his contacts in Japan to gain extra information ahead of the Group One showdown.

"It doesn't show a lot of confidence if you have a five-week training camp and play four friendly matches and still need to close the sessions," said the Dutchman. "We don't close our sessions."

Verbeek has been in Japan since Wednesday when he watched Japan's 5-1 friendly victory over Finland with his squad from Europe, South Korea and Australia arriving over the next few days.

"I didn't see anything new. We didn't have to analyse our opponents but get confirmation of what I knew already," added Verbeek.

"Japan are a good team with good players. They have had a long preparation, but we have no preparation. It's a big advantage for them.

"But our advantage is, of course, our players are experienced in international football. They know how to handle themselves with more or less no preparation and time difference."

Australia have already beaten Uzbekistan, Qatar and Bahrain, while Japan were held to a 1-1 draw by Uzbekistan last October before returning to winning ways against Qatar last time out after earlier also beating Bahrain.

Wednesday's game marks the midway point of Group One with Australia set to host Japan in June in the final group fixture.

"We'd like to win but we don't have to win," said Verbeek. "We can afford to lose the game with three home games to go. But Japan have to win the game because if they don't they will be in serious problems.

"Japan will have a game with the Uzbeks away. We were there, and that's definitely not another easy game. And, games like that can be crucial.

"So the pressure is totally on them. For us, we come here to play our best football trying to take three points."