Brazil have failed to win any of their last meetings against Group F opponents Croatia, Japan and Australia, suggesting their first round progess will not be as easy as anticipated.
The world champions had to come from behind to draw 1-1 away to Croatia in August and were extremly fortunate to draw 2-2 with Japan at last year's Confederations Cup.
Their last meeting with Australia, in the third-place play-off at the 2001 Confederations Cup, ended in a shock 1-0 defeat which cost coach Emerson Leao his job.
The Australians also managed to do something Brazil could not by beating Uruguay in the 2006 qualifiers, winning their play-off on penalties after a 1-0 win in the second leg gave them a 1-1 aggregate draw.
Brazil, meanwhile, drew home and away to Uruguay in the South American group.
Brazil coach Carlos Alberto Parreira, who has repeatedly warned against complacency, is worried about Australia's physical strength, Croatia's speed and the prospect of facing Japan coach Zico, one of Brazil's past greats.
Brazil, the only country to have played at every World Cup tournament, face Croatia first in Berlin on June 13 then Australia on June 18 in Munich and will hope to have their place guaranteed by the time the come face-to-face with their former captain in Dortmund on June 22.
Another worry is that Brazil have not played a serious match since last October, when they beat Venezuela 3-0 in a World Cup qualifier.
Various players have suffered either injury, such as captain Cafu and forward Ronaldo, or a loss of form, such as goalkeeper Dida, defender Roberto Carlos and striker Adriano.
Croatia coach Zlatko Kranjcar feels his side should join Brazil in qualifying. The East Europeans fell at the first hurdle four years ago but were surprise semi-finalists in France in 1998.
"Brazil are favourites, not only in our group, but for the title," he told FIFA's website.
"But compared to Japan and Australia, we have a good chance of qualifying for the second round. I think my team are a few points better than Australia and Japan."
Australia, in particular, will be keen to prove him wrong as they make their second appearance at the finals and their first for 32 years.
Australia, whose coach Guus Hiddink led his native Netherlands to the 1998 semi-finals and did the same with South Korea four years ago, have a heavy English influence with up to 10 premiership players in their likely squad
"This is the first chance we get to express ourselves and to show the world what we're made of, because we're definitely not going there to make up the numbers," said midfielder Tim Cahill.
Asian champions Japan, who have more overseas-based players than ever before, are under far more pressure than Australia and first-round elimination would be seen as failure.
