CARLTON didn't adjust to key forward Harry McKay going down in the early minutes, and it was a domino effect from there, according to interim coach Josh Fraser.

The Blues fell to Collingwood by 21 points on a brisk Saturday evening, despite being competitive and trading blows all night, but a lack of efficiency once in attack let the side down.

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"I thought (the Pies) were more efficient going forward… It's been an area of our game where we've had to try and address, and I don't think we're anywhere near the level that we need to be in that space," Fraser said post-match.

"Just going inside 50 and connecting, and you lose a target like Harry, and I don't think we adjusted well enough there.

"We had to make some adjustments, and I don't think we executed those adjustments well… our method (going inside 50) looked poor, I thought, I didn't think we won enough contests in front of the ball."

McKay came from the ground within the first 10 minutes following a knee-on-knee collision with teammate Sam Walsh. The forward tried to work through the pain and spent an extended period on the stationary bike, but was ultimately ruled out of the game at quarter time.

"The information we got was he wasn't okay to continue, so we'll get a scan on him and assess him early in the week," Fraser said.

"I can't, right now, shed any more light on Harry's situation other than he couldn't come back onto the field."

Fraser also confirmed that Adam Cerra – who was ruled out during the third term with hamstring tightness – was kept off the ground to prevent any further damage to the muscle.

With a young group, and playing a host of players to assess exactly who can impact in the next phase of Carlton, Fraser was realistic about what the result meant.

"When this (coaching) change happened, my message was that we wanted to make sure the club was in a better place at the end of our journey this season, and that was regardless of outcome. So, we know the work that's in front of us, you get some results, and you think you're fixed. We never thought that. We were looking at our game, we were committed to exposing different players to the system, we're committed to playing a certain way, and we're not quite there," Fraser said.

"(Collingwood) look like a team that has played their system for longer than what we have, we've still got some work in front of us that we've known."

For Collingwood coach Craig McRae, there was positivity that a relatively young, inexperienced side was able to play in a "pretty mature" manner.

"Just being able to ride the bumps of the game and embrace and accept what wasn't going our way at times, all sorts of things, and then finding the answers when we needed them," McRae said.

"It's managing the ebbs and flows of the game, embracing things that don't go your way. You've got to be able to throw your own punches, though. You can't just sit there and just take it… You've got to hang in there and we did that. We got 14 points up and then lost it reasonably quickly, and then came again."

Defender Isaac Quaynor came from the ground late with a forearm concern, and although he returned to the field, the club will monitor the defender during the week as it prepares to front up against Adelaide on a five-day break.

Scott Pendlebury (64 per cent game time), Jack Crisp (74), and Steele Sidebottom (76) all played fewer minutes than is typical for the senior trio, in preparation for the short turnaround, and the club expects defender Jeremy Howe to return for the crucial match.