The Springboks have won just one of their last nine matches in Australia, and never tasted victory in seven contests at this arena, but go into the game on Saturday (1105 GMT) full of confidence.
The South Africans have risen to number two in the world and are riding an eight-game winning streak that included two victories over Argentina in this year's Rugby Championship.
Springboks coach Heyneke Meyer has described the new-look Wallabies back line as one of the best his side has ever faced, but de Villiers said that while Folau possesses immense talent he has had just one Super Rugby season at fullback with the Waratahs.
"He's great under the high ball, he really contests well with the league and the AFL background," de Villiers said of Folau, who played rugby league and Australian Rules before switching codes to union.
"He's got fantastic pace, he's such a balanced runner. He's a big threat. He's obviously not the perfect player yet. He's still learning the game in a way and we'll try to expose that.
"We've got our plans that we made for this one."
While positivity has surrounded Wallabies coach Ewen McKenzie's team selection, there has been negativity towards the Springboks' inclusion of Zane Kirchner.
His selection at fullback pushes the popular Willie le Roux to the right wing and Bryan Habana across to the left, with Bjorn Basson missing out.
De Villiers said Kirchner, who makes his 25th international appearance but first since November 2012, deserves his place and has the backing of the whole team.
"Zane deserves it," he said. "There's been a lot of negative talk about him but I'm really happy that he's in my side.
"Zane is no different from any other guy who is selected for the game. You need to prove again and again you're good enough.
"I'm sure he'll have a great game. He'll have our backing."
Kirchner is one of three changes to the Springboks starting lineup with hooker Bismarck du Plessis and lock Flip van der Merwe coming in for Adriaan Strauss and Juandre Kruger, who both drop to the replacements bench in moves Meyer described as "purely rotational".