The loss means the Kangaroos will have to sweat on the outcome of other matches to determine their final ladder position.
Laidley didn't pull any punches when assessing his side's performance in Shannon Grant's 300th game.
"I'm here to apologise firstly to our supporters and secondly to Shannon Grant's family and his supporters," Laidley said.
"That was a disgraceful effort today and it all comes down to effort required. It was non-existent."
"We've blown an opportunity to finish fourth but we have another opportunity and that's the really important thing."
Laidley said his side would have to do some serious soul-searching if it was to be competitive in the finals.
"If you looked at today's performance, you would say (we have to address) everything because we didn't look like a football side out there today," he said.
But the North Melbourne coach said the team could rebound next week if it didn't dwell too much on the loss.
"We've got a final to win next week and that is very important to be able to realign yourself, refocus and get yourself ready for the final. Eight other sides would love to be sitting where we are right now," he said.
Laidley said he would not hesitate to make changes to the side and while he suggested some of his younger players may be worn out, he said the responsibility rested with his senior players.
"I thought our leadership group was pretty horrible today. It started from the top down," he said.
"We've had some good form in the VFL and you can't ignore that. We haven't ignored it all year and if they're fit and ready to go ...
"We gave Aaron Edwards an opportunity today and we've given Hamish (McIntosh) the last two weeks so we take them into a finals series probably not being match hardened.
"That is a question we have to look really closely at."
One forced change will be Leigh Harding, who is expected to miss at least a week with a medial ligament injury sustained in the first quarter.
