Schmidt, 56, was in charge of Ireland from 2013 to 2019 and masterminded a maiden win over New Zealand in 2016.
He was set to join New Zealand’s coaching set-up following the summer series, which begins on Saturday.
Ireland winger Mack Hansen is isolating after testing positive for Covid-19.
Ulster duo Iain Henderson and Rob Herring both picked up knocks in training on Saturday and will be scanned on Monday in Auckland, while Munster’s Niall Scannell has been added to the squad as additional cover at hooker.
New Zealand head coach Ian Foster, assistant coach John Plumtree and coach Scott McLeod have all tested positive for coronavirus, which has led to Schmidt being drafted in against his former side.
“Joe will come in for Tuesday and Thursday’s trainings this week, and we’re really grateful to have his help,” said Foster
“We’ve planned for this kind of disruption and we’ve got back-up plans and people on standby. Joe was one of those people we could call on.”
Centres David Havili and Jack Goodhue are also isolating after positive tests and did not travel to Auckland.
Andy Farrell’s Ireland side will also play three matches against the Maori All Blacks in their first tour of New Zealand since 2012.
