Crusaders coach Rob Penney said Wednesday his team was approaching a "massively important" stretch of the Super Rugby season, but must do so without All Blacks pair Will Jordan and Codie Taylor.
Jordan was ruled out of Saturday's clash with the Reds with a calf injury and Taylor has a hamstring strain.
No timeline for their return has been set.
Penney said it was not worth risking Jordan, despite what he said was a significant period in their season.
"He tried to get going, but it just wasn't worth pushing him," Penney said.
"He's had a big workload and this is just an unfortunate set of circumstances."
Taylor was coming off a four-try performance in the Crusaders' 69-26 win over the Fijian Drua on Friday, in the last match played at Apollo Projects Stadium.
Penney said his side would need to respond given the "next couple of weeks are massively important".
"We've got a really good plan. We've just got to get some results and keep building."
Johnny McNicholl will start in place of Jordan and David Havili also returns to the team.
The Crusaders and Reds are tied with 18 points on the Super Rugby ladder, sitting fifth and sixth respectively on point differential.