Hume picked up a groin strain in the 90-0 win against North Harbour at Forsyth Barr Stadium on Sunday.
"I suppose we are quite lucky because it should only be a week," coach Scott Manson said when asked how long the regular starter would be sidelined for.
Otago will get next weekend off as it has secured direct entry into the semifinals, so Hume will have another seven days to be fit for the playoffs.
Manson is confident that will be plenty of time, but Hume will be missed in the meantime.
"Her ability to spark something from nothing and wise head will be a loss. But it is a big opportunity for Hinemoa."
Hinemoa Watene will start at fullback in Hume's absence and outside back Cheyenne Cunningham will provide cover from the bench.
Watene is a reliable presence at the back and "she does the basics really, really well".
Left wing Kiana Wereta returns from a shoulder niggle, which means Teilah Ferguson drops to the bench, while Jess Kendall gets the start at lock ahead of Kate Smith.
"Teilah went well on the wing but probably made more of an impact when she moved into centre where she got her hands on the ball a bit more."
Manson said Kendall is an excellent lineout jumper and her handling is top-drawer.
"But we wanted her to be a bit more physical and Kate was giving us that. But in the last couple of games Jess has really stepped up in terms of her physicality on D and on attack.
"She has really put her hand up, so this is her shot this weekend."
Otago and Hawke's Bay are both unbeaten in the Championship. They have been so dominant, you can probably go ahead and ink them in for the final.
They have both already qualified for the semifinals, but tomorrow's game is far from a dead rubber. The winner is likely to host the final.
Manson is steeling his tight five for a tense battle. He believes Hawke's Bay will look to push its size advantage in that area before going wide, where it has plenty of talent.