Given the new six-six-six rule, North Melbourne star Shaun Higgins believes ruckmen are set to become some of the most important players in the competition in 2019.

Players like Max Gawn and Brodie Grundy - who were both named in the All-Australian team - will become even more valuable to their clubs, as teams can no longer put men behind the ball to counter-attack clearances.

The new rule states six men must be in each side's back line and forward line at each centre bounce, while the remaining six are between the arcs (four in the square, two outside).

Higgins believes having a quality ruckman will help at centre bounces, as opponents can no longer set up extra men off the back of the square.

"There wasn't anything stopping teams last year from having two or three off the back of the square. That happened at times. We probably didn't highlight it as much. Maybe the AFL were across it because of this rule change," Higgins told SEN on Monday morning.

"You'd drop your winger back or (bring your) half-forward up, but you (now) need your forwards and your defenders inside-50. You've got two wingers outside the square, and then it's just a battle of the midfielders.

"The quality of the ruckman as well is going to be really important because (when) guys like Maxy Gawn were getting on top in centre bounce, you'd protect the centre bounce off the back of the square or the side of the square.

"You're not going to be able to do that anymore."

First use in the ruck could give midfielders free space heading inside forward 50 according to Higgins, which would force defenders to make split-second decisions about when to leave their man.

"Once you break that first line of the midfielders, unless you're going to press off even numbers, you haven't got that extra coming off the back of the square," Higgins said.

"There's no protection at all.

"I mean, coaches are smart (and) there's a lot of coaches and football players these days that will analyse this closely, but it is opening up the attacking side of the game a lot more, and for the players that can break forward from stoppage, it can be really dangerous.

"Before you know it, you've broken that line and you are inside forward 50."