Shields picked up a leg injury in training and breakdown expert Kirifi has a bruised knee, said head coach Clark Laidlaw on Wednesday.
All Blacks centre Jordie Barrett will captain second-placed Hurricanes against the fourth-placed Chiefs in Hamilton as they battle for seedings and home advantage in the playoffs with two regular season games remaining.
Midfield partner Billy Proctor returns from a calf injury, while loose forward Caleb Delany was named on the Hurricanes bench following an injury lay-off.
"It's a bit like a nightclub -- it seems like one in, one out at times," Laidlaw said.
"We're hopeful they will all be fit, if not next week, then the week after," he said, referring to Kirifi, Shields and All Blacks prop Tyrel Lomax who is close to returning from a bruised ankle.
Loose forward Luke Jacobson will captain the Chiefs, who have won their last four games since losing to the Hurricanes in Wellington last month.
"They have a highly physical, fast and aggressive style, they were in the final last year, so we know what is coming. It's the perfect challenge," Laidlaw said.
Competition leaders Auckland Blues visit the struggling defending champions Canterbury Crusaders on Saturday.
A Blues victory in Christchurch would end Crusaders' slim chances of making the top-eight playoffs.
