The Chiefs depth is already being tested just one match into their Super Rugby title defence as they picked up several injuries in their 10-18 victory over the Crusaders in Christchurch.
The Chiefs won the match but are paying a price for the victory as forwards Ben Afeaki, Brodie Retalick, Kane Thompson, Tevita Koloamatangi and former All Blacks fullback Mils Muliaina all had to leave the field during the match.
Those players join an already lengthy list that includes loose-forwards Sam Cane, Tanerau Latimer, as well as Liam Squire and backs Gareth Anscombe, Bundee Aki, Robbie Robinson, and halfback Tawera Kerr-Barlow who was a late withdrawal from the match.
The Chiefs were so low on playing stocks that replacement hooker Nathan Harris came on to make his Super Rugby debut at blind-side flanker.
"We finished the game with a hooker on the short side and Crossy (Nick Crosswell) playing openside normally a lock or a six eight," Rennie told TVNZ
"We've got pretty good depth but she was a bit of a casualty ward out there."
There is however light at the end of the tunnel as Latimer is expected to be back for next week's match against the Highlanders in Hamilton.