Sonny Bill Williams: I have ironed out tackle technique

All Blacks star midfielder Sonny Bill Williams says a fault in his tackle technique has been ironed out - and potentially at just the right time.

Williams has taken note that Frenchman Jerome Garces is the referee for their Rugby Championship test against South Africa in Cape Town tomorrow morning.

Arguably the most influential figure in this year's drawn series against the British and Irish Lions, Garces made some key decisions, including the dismissal of Williams in the first half of the lost second test in Wellington.

Williams became the first All Blacks red card recipient in 50 years for his no-arms tackle on Lions wing Anthony Watson.

There has been no repeat in the Rugby Championship from 32-year-old Williams, who has started in all five wins.

"I've gone back and worked hard on my tackle technique.

"I feel like I've made steps in the right direction to hopefully not get a red card ... maybe a yellow," Williams joked.

Williams is reunited with first-choice centre Ryan Crotty, who was rested from last week's win over the Pumas in Buenos Aires.

The pair first combined for the Crusaders six years ago when Williams returned to New Zealand rugby after playing in the NRL.

Crotty feels better for the week off while others such as Williams have had a light week physically to help overcome a heavy travel schedule.

"It's all about attitude for us this week. The guys have got different plans in place," Crotty said.

"I'm fresh and chomping at the bit to pull the jersey on and try and fill it."