Starting loosehead Moody will have his thumb in a cast for six weeks after suffering a fracture during Saturday's 40-12 win over Australia in Auckland to secure the Bledisloe Cup.
With fringe contender Jeff Toomaga-Allen also injured, the uncapped Ta'avao is promoted ahead of next week's Test against Argentina in Nelson.
The 28-year-old made 22 appearances for the Waratahs across 2016 and 2017 before his form this year with the Chiefs caught the eye of New Zealand coach Steve Hansen.
