Brad Scott says North Melbourne's fadeout loss to Collingwood was as "disgusting" as any performance he's overseen in his six-season tenure at Arden Street.

North dominated the Magpies in the first half of Sunday's clash at the MCG, going into half-time with a 39-point lead that would have been bigger but for some wastefulness in front of goal.

But the Pies turned the game on its head in the second half, kicking 10 consecutive goals from the start of the third term to set up a 17-point win.

The North coach said after the game his players had lacked the mental ruthlessness to bury the Magpies when they had them at their mercy.

"We opened the door or left the door ajar for Collingwood and they ran through it and, regardless of system and structure and alterations to that, we just took our eye off the ball and it's as disgusting a performance as I've been involved with since I've been at North Melbourne," Scott said.

"(It was) just absolutely appalling and we've got to turn it around very quickly because at the moment, we're capable of what we're capable of in the first half and (can) really dominate a game, and then for whatever reason whether it's mental aptitude or mental strength (we don't finish the job).

"We use the right words (about) being tough and ruthless and relentless but it was anything but in the second half.”

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Asked whether North's inability to stem the Magpies' third-quarter momentum had highlighted a lack of on-field leadership, Scott said the Roos' designated leaders had stood up for most of the game, but had been let down by "too many passengers who don't toe the line".

Scott was adamant some players from Sunday's 22 would pay the price at the selection table ahead of next Sunday's clash against West Coast at Blundstone Arena.

"There are players who played well in the VFL yesterday and so players will be held accountable to a standard that the off-field leaders of the football club demand - if they can't meet those standards they go out," he said.

Scott said there had been no problem with North's on-field structures or systems during the second half of Sunday's game, saying his team's poor execution and its inability to win contests when it had Collingwood outnumbered had been costly.

"In terms of the way it was set up, it was all fine - it was just (our) execution was abhorrent," he said.

"There are two things you can't coach on game day - you can't coach skill errors and you can't control players getting beaten when we outnumber (the opposition) at the contest.

"That's as much mindset as anything."

North skipper Andrew Swallow was a late withdrawal from Sunday's game after failing to recover from the broken thumb he suffered in the Roos' round seven win over Essendon.

Scott said Swallow had been "close" to playing against Collingwood.

"His game is built around in-tight stoppage work and tackling and he couldn't do either of those at the level required, so we left him out," he said.