Ngarava has a lower-back injury and is one of three players from the squad that beat Bangladesh 2-1 in a home ODI series in July who will miss the Australia series.
Veteran batsman Taylor, 40, returns to the ODI squad for the first time in a year and will help with wicketkeeping duties as Clive Madande is also injured.
Graeme Cremer, who turns 40 on Saturday, has been recalled to help in the bowling department, more than two decades after he made his debut as a teenager.
The leg spinner last played an ODI for Zimbabwe eight years ago but was in their Twenty20 side that competed in a tri-series with Namibia and South Africa in Windhoek earlier this month.
Tanaka Chivanga, who is recovering from an Achilles tendon injury, is the other player from Zimbabwe’s most recent ODI series ruled out this week.
Zimbabwe host Australia at Harare Sports Club on Tuesday, Friday, and Sunday.
Zimbabwe squad: Sikandar Raza (captain), Ben Curran, Blessing Muzarabani, Brad Evans, Brendan Taylor, Brian Bennett, Craig Ervine, Ernest Masuku, Graeme Cremer, Innocent Kaia, Newman Nyamhuri, Ryan Burl, Tadiwanashe Marumani, Wellington Masakadza, and Wessly Madhevere.
