(theglobeandmail.com) Stuttgart, Germany — As Australia prepares to kick off its second World Cup campaign on Monday against Japan, there are still plenty of questions.

Is the strike force of Mark Viduka and Harry Kewell physically ready? Will there be after-effects from the ear infection that left set-piece specialist Marco Bresciano bedridden for several days this week? Can a side with a tendency toward physical play stay on the right side of the referees in the face of a FIFA clampdown? And can the Socceroos' defence tighten up when it counts?

In a group that features defending champion and top-ranked Brazil and No. 23 Croatia as well as No. 18 Japan, there is no room for error. The Australians, ranked 42nd by FIFA, know they need a result Monday in Kaiserlautern.

"If you can get three points in the first game, all you pretty much need is one point from the next two," midfielder Jason Culina said.

Hiddink took heart from a committed performance in a 1-1 friendly tie with the gifted Dutch, but was angry at sloppy play and lapses in concentration in a subsequent 3-1 win over modest Liechtenstein.

"It's rather crucial, the first game for both teams," manager Guus Hiddink said. "We must wake up. We cannot afford this on the first game."

Kewell (groin) and Cahill (knee) are both back in action from injuries suffered with their English clubs. Kewell's endurance is uncertain, however. The Australians played him just 60 minutes against Liechtenstein, hoping to stagger his return to action.

Hiddink says Kewell's progress leading up to the game will determine whether he starts or comes off the bench.

Against well-organized defensive teams, Hiddink says "it's good to have players who are very creative and that's why it's important to have the players fit who can make the difference. And that's a little bit my concern."

Viduka, the Socceroos' finisher, is suffering from a calf strain but the team says he will be ready come Monday.

Bresciano is also back practising. That's good news for Hiddink, who will be looking to use his set-piece deliveries to advantage against the Japanese.

Hiddink has also expressed concerns about staying away from yellow cards. The game against the Netherlands was a physical encounter, as Australia looked to use brawn at the beginning to upset the rhythm of the technically gifted Dutch.

Hiddink acknowledges he has some players who have a weakness for what he calls "easy yellow cards."

"We must be very careful about yellow cards or even worse," Hiddink said. "And I am referring to foolish yellow cards. ... Because always in the first match of a World Cup, referees are sometimes overexcited and they like to go with the yellow cards. And because the depth in the squad is not that broad, we need to be very careful."

This is Hiddink's swansong with Australia. The Dutch native, who took both the Netherlands and South Korea to the World Cup semifinals, will take over Russia after the tournament. Australia has yet to name a successor.