On Friday McKenna said: "I think they've shown their inability to sustain games. I think they're vulnerable after quarter-time, let's be honest."
And on cue, North Melbourne won its 10th first quarter in 11 games before fading out.
Whereas previously the Kangaroos have fallen late in matches – blowing four final quarter leads to lose by less than a goal – this time, the entirety of the final three terms proved costly.
The Roos lost the inside 50 count 56-22 after quarter-time and were lucky to stay as close as they did.
But Scott emphatically defended his team's mental capacity, saying it was not a concern.
"Not in the slightest," he said.
"We started well, there's no capitulation, just an inability to do the fundamentals well.
"Others can talk about it if they want, but that's not an issue as far as I'm concerned.
"We've got fundamental things we can do really well, but the conditions were the main thing that we didn't adapt to and that's our responsibility and we have to fix that."
With a 4-7 win-loss record leaving the Kangaroos two wins outside the top eight as they enter the bye, Scott said he was not even thinking about finals.
"Not an issue for me. That's so far into the future. We've got to start playing footy that's worthy of that," he said.
Against the Suns, he said it was his team's lack of ability to adjust to the wet conditions and win the contested ball that cost it.
"We've got some work to do when we play in those conditions," he said.
"Contested possessions - before this game we were top four in the completion and we got beaten. They outnumbered us, outworked us.
"They're showing now what everyone's known for a long time. We're bitterly disappointed with our performance but we knew we were going to be in for a tough game."
Michael Whiting covers AFL news for AFL.com.au. Follow him on Twitter: @AFL_mikewhiting
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