Brad Scott says North will need to be wary of Melbourne's talls, despite the Demons missing Max Gawn and Jake Spencer through injury. 

Cameron Pedersen, a 193cm forward, is Melbourne's makeshift ruckman in their absence and Jack Watts, Tom McDonald and Sam Frost provide support.

The Demons have consistently conceded the hit-out count since Gawn and Spencer suffered injuries, with Adelaide ruckman Sam Jacobs amassing 74 against them on Saturday night.

But that didn't stop Melbourne winning the clearances 49-38, including 18-6 in the centre, in a 41-point victory over the Crows at Adelaide Oval.

Young bulls Jack Viney, Clayton Oliver and Christian Petracca, as well as veterans Nathan Jones and Jordan Lewis, enabled the Demons to turn a potential problem into a strength.

The Roos copped a hiding in centre clearances (10-19) and contested possessions (133-170), among other areas, in their 42-point loss to Sydney at Etihad Stadium.

"The ruck dominance against Melbourne the last three weeks hasn't translated to clearance dominance," Scott told reporters.

"So it's a bit of a concern for the game … I'm sure Melbourne would like to have Max Gawn. There's no doubt about that. But clearly in the clearance area it hasn't hurt them.

"We've got to be really careful in the game that we don't breed out the really high quality, potentially a little bit immobile ruckman who can get their hand to it at the contest.

"There are a lot of rules coming in that are detrimental to ruckmen."

Scott said the decision to ban the 'third man up' was countered by the AFL's wish for fewer stoppages, including a tightening of the deliberate out of bounds rule.

He stopped short of writing a eulogy for ruckmen, but said clubs were increasingly looking for mobile options over traditional tap specialists.

"I've always thought a key tenet of our game is that anyone can play – whether you're super tall, super small, you're a good inside player or a quick outside player," Scott said.

"We don't want to breed those guys out of the game just making it impossible for them to play.

"I understand that fans want to see the ball in play, but our game, at its roots, is a brutal, contested game and that usually results in stoppages."

The Kangaroos will make at least two changes, with emerging pair Trent Dumont (concussion) and Jy Simpkin (shoulder) being forced outs.

Jarrad Waite, Aaron Mullett, Taylor Garner, Declan Mountford and out-of-favour former skipper Andrew Swallow are the potential additions.

Scott refused to reveal whether Swallow, after being dropped before round six, would return to the senior side as North seeks to beat the Demons for the 16th straight time.

"He's responded to the coaching points we put to him and we know what a fierce competitor he is and he's a player who's given his heart and soul to this football club," he said of Swallow.

"I think I said last week that we've far from seen the last of Andrew Swallow, so we'll get through training today and then finalise our side."