North Melbourne has put more of an emphasis on its tackling in the wake of its humiliating Preliminary Final defeat to Sydney according to vice-captain Drew Petrie.

The Swans had 61 tackles (11 more than North) and 356 disposals (27 more than North) in the game that denied North a grand final berth and the Roos are working hard to make amends.

"We are still doing a lot of tackling. We've got two dedicated tackling sessions a week with the specialised tackling and grappling coach," Petrie told The Age.

"So that puts more emphasis on the notion that we're not just about attacking.”

The Kangaroos made some significant tweaks to their game-plan last season striking a better balance between attack and defence, but allowing tackles to be easily broken remains an issue according to the key forward.

"I think last year we were a very good attacking side, we moved the ball quickly from end-to-end really well.

"But on the flip side, teams were able to do the same to us - they went coast-to-coast on us a lot and got through our defence a little bit too easily.

The Swans’ relentless attack on the player and the ball showed the North players what’s required of them if they wish to be contenders this year.

"There is just no escaping not tackling and chasing blokes within training.

"The Sydney game, if you look back at it, they just rushed through us. But then, when they tackled us, they smashed us and got the footy back. So that's been identified.

"Yes, they beat us convincingly on the scoreboard. But the 'why' was that they were able to bust through our tackling efforts and defensive pressure set-ups."

The Swans were able to run the ball into their forward 50 on 69 occasions (compared to 44 times for North) and take a concerning 27 marks inside the arc. Petrie said the Roos were ‘smashed’.

"There is a big focus on defence. A lot of the stuff we look at on a Monday morning will revolve around that.

"So that comes down to tackling and a bit of structure stuff as well, which we've had to change.

"The game is always changing, yes, but if you look at the top teams last year – Hawthorn, Sydney, Fremantle, Port Adelaide - they all are very, very solid defensive teams again," he said.

"I haven't seen a recipe yet that says you can win a premiership without being good at defence."