Sititi, 22, who was also awarded the All Blacks Player of the Year award in 2024, was seen by a surgeon during the week who diagnosed a high ankle injury that will require surgery.
It will be another three weeks before a return-to-play protocol is established for him. Given the series against France starts next weekend, that will rule Sititi out for the three Tests in Dunedin, Wellington and Hamilton.
Sititi, who played nine Tests in his debut season, has endured an injury-plagued second year at the top level of the game. During last November's northern hemisphere tour, he sustained a knee injury that delayed his start to the DHL Super Rugby Pacific campaign for the Chiefs this year.
Crusaders No8 Christian Lio-Willie has moved from injury cover into the squad to replace him, while 36-Test flanker Dalton Papali'i, who was omitted from the squad named earlier in the week, has joined the squad as injury cover for Chiefs captain and loose forward Luke Jacobson, who is working through concussion protocols in the wake of the Super Rugby Pacific final at the weekend.