Since the end of the 2010 World Cup and the arrival of Holger Osieck to take charge, Australia have slipped from 24th in the rankings and number one in Asia and now face falling out of the top 50.

They are now third in Asia behind Japan in 29th place and South Korea who moved up five spots to leapfrog the Roos and take up 42nd place overall.

The latest setback comes after the Socceroos struggled to draw 2-2 with Oman in Sydney last month, with the hopes of making it to Brazil 2014 now hanging in the balance.

Elsewhere, Ecuador have entered FIFA's top 10 for the first time in their history after two big wins in March, while Croatia have risen to fourth.

After thumping El Salvador 5-0 in a friendly and then cruising past Paraguay 4-1 in a World Cup qualifier last month, Ecuador have reached second in the CONMEBOL standings, while also rising to 10th in FIFA's world rankings.

The breakthrough of Reinaldo Rueda's side sees Russia drop out of the top 10, while Croatia, who defeated Wales 2-1 and Serbia 2-0 in March, have climbed five spots to fourth, equalling their best-ever ranking.

The top three of Spain, Germany and Argentina stay the same, while Portugal complete the top five after improving from seventh.

Colombia remain sixth, England (down three) take up seventh spot and Italy (down three) sit eighth, while the Netherlands (down one) and Ecuador form the top 10.

Alongside Croatia, Denmark and the USA are the big improvers in FIFA's top 30 having both risen five positions to 20th and 28th respectively, while Belgium have climbed three spots to 16th.

Sweden (down to 24th) and Japan (down to 29th) joined England and Italy as teams in the top 30 who fell three positions.

New Zealand improved two spots to 86th, while Wales soared 22 spots to 49th, Scotland plunged 11 places to 77 and Ireland moved up one to 39th.