The Socceroos face a must-win match in the Qatari capital with Holger Osieck's men still searching for their first victory in the final phase of World Cup qualifying.

Australia were stunned in their last outing after Jordan prevailed 2-1, leaving the team with just two draws and a loss in three fixtures.

The Socceroos are already eight points adrift of group leaders Japan and sit level on points with a determined Iraq side led by Brazilian legend Zico.

Wednesday's clash will be the first meeting between the nations since Australia overcame Iraq 1-0 in the quarter-finals of the 2011 Asian Cup courtesy of Harry Kewell's extra-time winner.

"I can't remember an easy game against Iraq or in Asia in general but Iraq are definitely one of the toughest opponents we have come across," Valeri said.

"We are definitely going to have to be at our best and play as team."

Valeri, who returns to the national team fold after missing the Jordan game through injury, knows victory against Iraq is pivotal to Australia's chances of progressing to the World Cup finals in Brazil.

"It would be a good time to start building some results to gain confidence because qualifying for Brazil is the most important thing for us," the Sassuolo midfielder said.

His Socceroos team-mate Mile Jedinak is also expecting a difficult contest against the 2007 Asian Cup champions.

Iraq will face five-time World Cup winners Brazil in a friendly match in the Swedish city of Malmo as preparation, while the Australian's will spend a week training in Doha.

Zico's team consist of no less than 20 Iraqi-based players and while Jedinak is under no illusions of the task at hand, the Crystal Palace midfielder is hopeful of repeating last year's success.

"We know what sort of team they are," he said.

"They are a very difficult team. They have a lot of games together as a unit and they are almost like a club team in a sense because they have so many caps together, the majority of them.

"We know it's going to be a very tough game in conditions they are more used to but that's not an excuse for us.

"We done it last time in a tough game at the Asian Cup, which might have went either way but I think we deservedly won that game and hopefully there will be more of the same come next Tuesday."

With Australia in need of a result against Iraq, Osieck has turned to Utrecht speedster Tommy Oar in one of three changes to the squad that lost to Jordan.

The Brisbane Roar product has been rewarded for his fine domestic form and is in line for his first cap since the Socceroos' goalless draw against the United Arab Emirates in January 2011.

And despite the pressure surrounding Australia's upcoming fixture, Oar is confident of claiming a positive result.