Australia needed a 4-0 victory over Thailand in their final Group A game to advance to the last eight after drawing with Oman and crashing to a 3-1 defeat to Iraq.

And Arnold believes the do-or-die attitude shown by his side during the victory over co-hosts Thailand will see his side through against the defending champions.

"It's going to be a very difficult game as Japan have shown some good form in the group stage. We have grown in momentum in our three games and we are looking forward to the game," he added.

"This game has come at a great time for us; maybe the first two games against Oman and Iraq shocked the players in showing how difficult the tournament is. You are going to have to come up against one of the favourites sometime and I'm quite happy to come up against them now.

"Japan have played a slow, patient style up to now in Hanoi but a fast pace would suit us because we have got players who thrive on fast football and love playing fast attacking football."

The Socceroos are without the suspended Luke Wilkshire, who collected a second yellow card during the victory over Thailand, but with Lucas Neill returning from a ban, Brett Emerton will take up the vacant midfield role on the right while Michael Beauchamp and Mark Milligan will join the West Ham man in a three-man central defensive backline.

"I think Japan deserve to be favourites. If you look at the group games they have been in better form than us," added Arnold, who enjoyed two years in Japan with J.League side Sanfrecce Hiroshima.

"Their local players in the J.League are in the middle of their season so at this stage they deserve to be favourites, but saying that, Australians love to be underdogs. We had our first final against Thailand, we came through that, and this is our second one."

Japan coach Ivica Osim believes Saturday's showdown is his toughest task since taking over at the helm of the continental champions.

Japan are aiming for a third straight title and a fourth in total but have their way blocked by an Australian team that have started to find their feet after a poor start to the tournament.

"I see this as the most difficult match [in my spell with Japan]," said Osim, who replaced Brazilian Zico after last year's World Cup finals.

"Japan haven't played many opponents at this level, except Ghana [on October 4] and that was a friendly.

"Australia have overcome their difficult period and are improving. No team can play perfectly and a team who can manage to win even when they are not in good shape is a strong side, as Brazil did in the Copa America."

Osim's only concern centres around midfielder Keita Suzuki, who trained separately from the rest of the squad on Thursday after complaining of a pain in his calf.