Chiefs coach Colin Cooper is believing in the depth of his squad as they battle injuries early in their campaign.

The Chiefs' injury woes have intensified and, just one game into their season, their bye week looks like it can't come quick enough.

But first they must pick themselves up from their 45-23 defeat to the Crusaders in Christchurch and front up to another tough Kiwi derby against the Blues at Eden Park on Friday night.

It's certainly going to be a week where the squad's depth is tested though.

HANNAH PETERS/GETTY IMAGES Tim Nanai-Williams has been ruled out for the season with a shoulder injury.

At Monday afternoon's training Chiefs coach Colin Cooper confirmed utility back Tim Nanai-Williams was gone for the season, requiring surgery on a shoulder he injured in the final pre-season game against the Brumbies on the Sunshine Coast.

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It's cruel luck for the 28-year-old, who last year had shoulder and ankle problems, and is off to French club Clermont Auvergne at the end of this campaign.

PHOTOSPORT Co-captain Charlie Ngatai is set to miss at least a couple of weeks with a knee injury.

Then there's newly instated co-captain and fullback Charlie Ngatai (knee) and lock Dominic Bird (shoulder), who left AMI Stadium gingerly, with Cooper guessing each would be out for a couple of weeks.

A trio of players are also going through concussion protocols, with loose forward Mitch Brown and bench backs Marty McKenzie and Sean Wainui all taking knocks on the night. Brown had looked the groggiest on the night but is said to be in the best nick of them, with no symptoms.

Cooper said there wouldn't be any returnees from the casualty ward this week either, with props Kane Hames (illness), Mitchell Graham (leg) and Sefo Kautai (foot), loose forward Tyler Ardron (hand) and utility back Sam McNicol (concussion), already out. All Black Hames had returned to training last Thursday but Cooper said he "had to go through a process".

KAI SCHWOERER/GETTY IMAGES Dominic Bird was one of several Chiefs to come out of the Crusaders game with injury.

It makes for a hell of a test of character early in the season, but Cooper remains positive.

"It'll have an effect, no doubt, but I've got a lot of confidence in the depth we've got, that we can bring others through," he said.

A decision on if someone would take over Ngatai's co-captaincy duties was still being worked through, as was the call on a replacement for Nanai-Williams, with former Chief Declan O'Donnell - having also been under Cooper's tutelage at Taranaki - training with the side on an afternoon which also saw former All Blacks assistant coach Wayne Smith in attendance as part of a gig mentoring some exchange players from Japanese club Kobe.

While Cooper wants to see his side more accurate and disciplined against the Blues, he was also keen on chatting about the incident that swung the game - Lachlan Boshier's 71st minute yellow card penalty try for his contact on Ryan Crotty's head.

"The law says leave the head alone... and, yes, you've got to look after players and you've got to look after the head, I agree with all that... I just think there has to be a common sense clause in that," he said.

"When two players are going so low, do you let him score the try and not give a yellow card away?

"You've got to get lower, and I don't know if they can get any lower. If it was a reckless arm or if it was intent or going in without looking [then punish that], [but] I think Lachie was looking to try and grab the ball to hold him up."

Asked if he was going to take his concerns higher, Cooper said:

"I've got too busier job, I've moved on. I think just having a conversation about it is all we need to do."

Meanwhile, with the dates of the mid-season All Blacks camps having been made public last week and the Chiefs to be stripped of all their top brass against the Sharks in Durban on May 20 and be the only team to actually be affected for a game-day, Cooper was philosophical.

"Plan. Depth. Be ready. It's going to happen," was his response, before being equally blunt on whether he and his team had gone back with much resistance to the idea.

"We've had a lot of conversations."