Sydney: Australian captain Michael Clarke has rated the upcoming tour of South Africa as tough a challenge as there is in world cricket.
The Australians will play two Twenty20, three one-day and two Test matches against South Africa starting in mid-October.
South Africa currently sits second in the world Test rankings, behind only England and two places above Australia, a leading daily reports.
"They are a very good team and they are ranked very high in all forms of the game," Clarke said in Sydney on Tuesday.
He added: "They have had a lot of success in their own country, so it`s as tough a challenge as you face in world cricket, no doubt."
While Australia won their last Test series in South Africa, Clarke said some of their players were better for added experience and he rated them a very skilled unit.