Pumas first five Juan Martin Hernandez has been labelled "the best player in the world" by his Springbok opposite Butch James in the build-up to this weekend’s semifinal between the two nations.

Hernandez has been instrumental in guiding Argentina through to its first ever RWC semifinal appearance, including two memorable victories over France and Ireland.

He looms as the Pumas’ key man again when they line up against the Springboks at Stade de France.

"I think he is the best player in the world at the moment,” James says.

"I am not to sure if fly-half is his position, but he is by far the best rugby player in terms of skills and everything that goes with it.

"I think that with a bit of space he would be better at full-back.

"He has got good hands; he has got a big boot; he can step; he has got speed - he's got everything."

However, James isn’t losing any sleep over the problems Hernandez may cause the South African’s defensive line.

"I don't think it will be too hard.

"I've got the incredible Schalk Burger on my inside - so he should be helping me a bit - and Francois Steyn outside - so I'm not too worried about him.

"We will be able to handle him.