Williams missed last week's win over the Cheetahs in Auckland, having suffered a head knock the week before against the NSW Waratahs.
It's a timely return for the 33-Test All Black, who has played just four games since his comeback from a ruptured Achilles tendon.
He'll form a midfield partnership with George Moala on Saturday as he seeks to push his way back into the Test fold.
Meanwhile the Crusaders get their captain and All Black lock Sam Whitelock back their match against the Chiefs in Suva on Friday night.
Whitelock missed last week's win over the Hurricanes as part of a two-week suspension.
He replaces the injured Scott Barrett in the starting lineup.