Crusaders coach Todd Blackadder has leapt to the defence of the "unbelievable" Sonny Bill Williams, who has been the target of scathing criticism from Springboks boss Peter de Villiers.

Speaking to his home newspaper The Press from South Africa, where the Crusaders are preparing to play the Central Cheetahs this weekend, Blackadder was not prepared to get into a public debate with de Villiers.

But he said rugby needed heroes like Sonny Bill, who was a "fantastic player and a great role model".

Before the Crusaders monstered the Western Stormers last weekend, de Villiers was dismissive of Williams' flamboyant offloading skills, which he described as "a bad example to aspiring youngsters".

"I hope he will mature his game," the Springboks coach said. "He's doing everything wrong what rugby principles require of you in the game.

"Backhand passes shouldn't be the norm ... it has become the norm, now everyone wants to do that kind of nonsense."

A youngster watching Williams would get the wrong impression of the core skills needed to play the game, de Villiers added.

"He'll spend hours and hours on the things that are not important and never master the most important things of rugby."

Williams starred in the Crusaders 20-14 win over the Stormers with his offloads and powerful running and winning praise from Blackadder.

"This game needs heroes. All the kids are running around calling offloads 'Sonny Bill Williams'," he said.

"It's like when Jonah (Lomu) was playing. We should embrace those people with natural, special gifts. It's great for the profile of the game.

"I think Sonny's a fantastic player and a great role model. He's a real professional and he seems to be able to express himself ... He's got an instinctive ability which is just unbelievable."

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