STOPPING the Western Bulldogs' run out of defence looms as the key to a North Melbourne victory this Saturday night, says Roos half-back Jamie Macmillan. 

The Kangaroos are eighth on the ladder, with the Dogs one spot above them. North faces a tough final four weeks of the season, with all of its upcoming opponents ensconced in the finals race. 

"They're the No.1 transition team in the competition at the minute, from their back half," Macmillan said at Arden Street on Friday.

"They're moving the footy as well as anyone. Speaking about injuries, they've had a fair few as well, but guys keep stepping up for them."

Matthew Boyd returns from Achilles soreness to bolster the Dogs' defence, while Dale Morris also comes back after hamstring soreness. 

For Macmillan, improved aggression against Collingwood and St Kilda over the last two weeks has been critical to winning those games, and ending a run of five consecutive losses. 

"The first nine rounds of the year, our pressure was exceptional," he said. 

"(We) dropped away a little bit through the middle part of the year. 

"The last couple of weeks we're back to our best and had the best results in that area that we've had in a long time." 

After starting the year 9-0, injuries and a loss of form combined to cruel the Roos' top-four hopes. 

Hip surgery for Jarrad Waite has been the latest affliction to hit the club. 

Macmillan said teammates had drawn upon the Shinboner spirit his club is famous for, and would continue to use it. 

"Shinboner spirit is something that's really hard to define, but it sort of comes out when you need it the most," he said.

"We don't run out there thinking 'the Shinboner spirit – we're going to need that today', but when the going gets tough, it's expected that if you're playing for the North Melbourne footy club and you're wearing our jumper, you're going to put your head down and work hard."

Macmillan spoke to Waite before training and said the forward was not using crutches, despite having gone under the knife in recent days. 

"He's positive that he'll get back towards the end of the year, but it's too hard to know," Macmillan said. 

The 24-year-old North leader will line up for his 100th match on Saturday.

"It’s taken a little longer than I would have liked. A couple of injuries along the way but it’s been nice to get some continuity this year," he said.

A fractured leg cost him much of the 2014 season, while he has also had to deal with hamstring and Achilles injuries.