The Chiefs' locking crisis has taken a turn for the worse, with Dominic Bird to miss the rest of the Super Rugby season.
The two-Test All Black has decided to undergo surgery, after injuring his shoulder in the season-opener against the Crusaders.
The Chiefs have already lost Mitchell Brown (knee) and Fin Hoeata (shoulder) for the remainder of the competition, while Michael Allardice remains sidelined with a groin injury.
Coach Colin Cooper has been left searching for some new tall timber, with Bay of Plenty's Baden Wardlaw and Waikato's Sam Caird training with the squad.
"It's a bonus when we don't have an injury - it's like a bonus point" Cooper quipped.
"Our lock situation is still a concern at the moment so we're just going through a process to make sure the fit is right for what we need."
However, he was impressed with how his players were responding to the challenge with other members of the squad stepping up against the Sunwolves last weekend.
"It was great to see the competition going on with guys like Tyler Ardron coming in, and making the most of their opportunity" he said.
Cooper is hoping to have co-captain Charlie Ngatai available against the Highlanders after having been sidelined with a knee injury.
The match in Hamilton on Friday night will be fellow co-captain Sam Cane's 100th for the Chiefs.
"It's a special moment and there will certainly be no excuses to get into this battle," Cooper said.
"What Sam talks, he walks," he said. "When you get a leader like that, the rest follow."
