Group D: Australia v Serbia preview

Socceroos midfielder Brett Emerton does not believe Australia will struggle physically against Serbia on Wednesday despite being reduced to ten men in their opening two World Cup matches.

Both Tim Cahill and Harry Kewell have been dismissed so far in the competition, seriously denting their chances of advancing to the knockout stages.

They go into the Serbia game needing a win and for either Ghana to beat Germany, or Germany to beat Ghana by a big enough margin for Australia to turn around a five-goal difference on the Africans.

It remains a long shot but Emerton is adamant the Socceroos will not be lacking physically for their crunch encounter.

"If we can play a game with 11 men, we will probably feel like we're running on air," joked Emerton.

"I think physically the team's in very good shape, all the boys have worked exceptionally hard coming into this World Cup, so I can't see that being a problem."

On a psychological level, Emerton said the Socceroos are more motivated than ever having endured two red cards in the two games to date.

"We know we haven't got the rub of the green, which is disappointing, we've played the majority of this World Cup with ten men so far and both have been very, very harsh red cards," he added.

"It's disappointing to lose Harry, but we get Tim back and after our good performance against Ghana, we should go into this match full of confidence," he said.