South Africa has put a question mark over Sonny Bill Williams' defensive skills in sevens, and are eager to test him in Wellington at the end of the month.

Williams has been named in New Zealand's squad for their home tournament of the world circuit and is tipped to make the cut to take the field at the Cake Tin next Saturday and Sunday.

South Africa coach Neil Powell made it clear that defence would be the biggest challenge for Williams ‑ who has changed attacking plays in 15s rugby with his remarkable offloading skills.

Powell says one player can’t make a team as sevens is all about team work.

He says it will be interesting to see how Sonny Bill goes and adjusts to the intensity and speed of the game.

South Africa and Fiji are tied at the top of the table after two rounds with New Zealand 10 points behind in seventh.

Source: stuff.co.nz