"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."