The physical second five-eighth suffered a concussion during the 34-26 win against Hawke's Bay on October 5.
She is symptom-free but is being stood down this weekend.
She should be available for the final if Otago makes it.
Coach Scott Manson said it was a blow to lose the team's only Black Fern, but he was confident Teilah Ferguson would fill Moata'ane's boots nicely.
"We'll miss her hard, direct running. But we've seen with Teilah Ferguson that she has come on leaps and bounds this year," Manson said.
"I'm sure she will do really well and she performs a similar role to Tina anyway."
There are two other changes to the starting side which edged Hawke's Bay.
Classy fullback Sheree Hume returns from a groin strain and lock Kate Smith regains her starting spot at the expense of the skilful Jess Kendall.
Smith got the nod due to her superior physicality and consistency.
"Her defence is really good too, and she is that typical old-school lock who gets in and does the hard work.
"Jess definitely has a better skill set and we will look to use her in the second half."
In other changes, Hinemoa Watene drops to the bench to make room for Hume, and pivot Hannah Stolba has returned from a trip to Japan and will start from the bench.
Otago dispatched Tasman 58-15 in Oamaru late last month and should be too strong for its opponent.
Manson does not believe complacency will be an issue.
There is a home final to play for and that is pretty good motivation, he said.
"The girls are pretty driven to go out there and send a message, do a job and move on to next week."
The Spirit is undefeated this season.
Otago v Tasman
Dunedin, tomorrow, 2pm
Otago: Sheree Hume, Trisha Hopcroft, Amy Du Plessis, Teilag Ferguson, Kiana Wereta, Rosie Kelly, Rosie Buchanan-Brown, Greer Muir, Morgan Henderson, Bree Thomas, Julia Gorinski, Kate Smith, Eilis Doyle, Tegan Hollows, Isla Pringle. Reserves: Gemma Millar, Claudia Hobbs, Paige Church, Jess Kendall, Hannah Stolba, Hinemoa Watene, Cheyenne Cunningham.