Brad Scott unleashed rare sprays on his players at the quarter and half-time breaks in North Melbourne's win over St Kilda on Saturday, admitting he used some "choice words" to spark the lethargic Roos into action.

North looked headed for a costly defeat against the Saints at Blundstone Arena when they trailed by 20 points at the main break.

St Kilda's lead did not truly reflect their dominance to that point. They led the inside 50s 37-15, uncontested marks 55-32 and, in the first quarter, their pressure had contributed to North's lopsided 36-57 kick-to-handball ratio.

Scott told reporters after the game North had "invited" St Kilda's pressure by handballing too much, while his forwards had allowed the ball to be rebounded from their forward 50 too easily.

The Roos coach said the one basic he had demanded from his players was a vastly improved work rate. And he didn't hold back when asking for it.

"There were some choice words and I should apologise to some of our staff who copped it through no fault of their own," Scott said.

"But sometimes it's the closest person who cops it."

Scott was satisfied that his message got through, with North riding a nine-goal third quarter to a 37-point win.

However, as pleasing as the 57-point turnaround was, Scott was concerned it had taken his players "much too long" to adjust to St Kilda's pressure.

Lindsay Thomas personified North's down-and-up performance.

The classy small forward was held to three possessions and no goals in the first half and suffered several discipline lapses that saw him give away four free kicks for the game.

At the 11-minute mark of the third quarter, he gave away a 50m penalty that allowed Jarryn Geary to goal and stretch the Saints' lead back out to 21 points.

But just a minute later Thomas redeemed himself, kicking a clever dribble goal. He then added another two majors before three-quarter time to help the Roos get out to a 25-point lead.

"You saw the best and worst of Lindsay today," Scott said.

"It's a credit to him that he responds really well, but he can't have those moments of poor discipline which cost the team.

"But to his credit he got back on the bike and was a pretty significant reason for us getting back in the game.

"He's been really good on that front since returning to the senior side and he's got to continue that, otherwise he'll be under pressure again."

North vice-captain Jack Ziebell was reported for striking Jack Newnes when he tried to the spoil the Saint in a marking contest midway through the second quarter.

Scott suggested he did not think there was much in the incident but said he had not seen a replay.

"From my vantage point it looked like a very slightly late spoil," he said.

"The kick was directed to [Ziebell], it fell short.

"The authorities will judge that on its merits. It's really hard for me to make a judgment and even if I did make a judgement, I can't say anything."