SYDNEY - A mounting injury list is threatening to spoil Australia's perfect start in this week's round of Asian 2010 World Cup qualifiers. The Australians are clear at the top of the Group A standings after winning their first two matches and victory in Bahrain on Wednesday would leave them in a strong position to qualify for South Africa. The Socceroos thrashed Qatar 4-0 at home last month but coach Pim Verbeek will be without several key players for the return match, with Scott McDonald, Brett Emerton, Vince Grella, Craig Moore, Matthew Spiranovic and Mark Milligan all ruled out. However, Bahrain, who have just one point from their opening two matches, will also be depleted with four players suspended. "I think this is going to be a very tough game," Australia captain Lucas Neill told reporters. "Obviously, the fact we've put ourselves out in front now, we're there to be beaten. "There won't be a chance for complacency because the manager and I won't allow it. We're here to win another game and if we can win that game then what a fantastic position we'll be in." Wednesday's other Group A match between Japan and Qatar in Doha is crucial for both sides, who are level on four points, although the Japanese have a game in hand. LAST QUALIFIER Japan could only draw 1-1 at home with Uzbekistan in their last qualifier and will be without defender Yuji Nakazawa and goalkeeper Seigo Narazaki. Japan, whose coach Takeshi Okada is coming under increasing fire over the team's performances, enjoyed a 3-1 friendly win over Syria last week but remain wary of Qatar. "It was great that my players kept their motivation high. The team tried almost everything I wanted to test," Okada said. "But we mustn't forget that this result won't guarantee us anything for the Qatar match." One of the most eagerly-anticipated games takes place in Riyadh where Saudi Arabia host South Korea. The teams are level on four points, along with Iran and North Korea, in Group B and only the top two qualify automatically. South Korea lead on goal difference after beating United Arab Emirates 4-1 at home last month and drew 1-1 with Qatar in a friendly last week to acclimatise to conditions in the Gulf. Saudi Arabia, bidding for their fifth straight appearance at the World Cup finals, could not have been more impressive in their 4-0 friendly win over Bahrain last week but may be without regulars Yasser Al Qahtani, Hussein Abdulghani and Saad Al Harthi. United Arab Emirates, the only team in either pool yet to register a point, host Iran in Dubai. Wednesday's matches are the last Asian qualifiers this year with the next fixtures scheduled for February.