It is that toughness, his willingness to attack the football, that fellow Roos forward Ben Brown most admires about how his teammate plays.

North Melbourne fired Petrie, Nick Dal Santo, Brent Harvey and Michael Firrito last week, saying it was time to start giving their younger players more opportunities.

The Kangaroos are preparing to take on Adelaide in the first round of the finals next weekend with the knowledge that should they lose, it will likely be those stalwarts' last AFL game – certainly their last for North.

Brown toes the party line when he talks about how he felt about the announcement.

It was a shock, he said, but understandable – that's footy.

But Petrie, in particular, has been a mentor and Brown is widely considered the 33-year-old's heir in North's forward line.

Brown said he looked up to Petrie for his dedication and professionalism.

"[I like] the way he goes about his preparation, everything he does at the club he does to try to improve, which is something that is quite rare," Brown said.

"That's something I've tried to take on myself, to make sure I make the most of my time here and really look to improve."

Brown was grateful for how the four delisted players had dealt with the announcement, joining in training as usual and encouraging their teammates to focus on playing finals.

"They all want a premiership, they understand that difficult decisions have to be made in a club scenario. I understand that too," he said.

"It was tough to begin with, but they've really focused us on the task at hand."

North players had Tuesday and Wednesday off, taking advantage of the league-wide bye week to rest.

Brown said he put his feet up and nursed a couple of sore spots after the Roos' game against GWS last weekend.

North could not summon a win against the Giants, even though it will likely be the last time Petrie, Harvey, Dal Santo and Firrito will play to a home crowd, but Brown starred in the first half, booting three goals.

Petrie has struggled for form this year and managed just four possessions against the Giants.

Should fellow veteran Jarrad Waite make it back from injury, coach Brad Scott may have to consider dropping Petrie, which would be a sad end to a high-flying career.

Brown said North had to look at the things they were doing well in the first half of the season, when they won nine consecutive games and were sitting at the top of the ladder.

Adelaide's forward line was a real strength for them – Josh Jenkins and Eddie Betts will be a challenge for North defenders to contain, he said.

"It obviously helps when you've got two star players dominating, that's even without considering Tex Walker and Charlie Cameron, Mitch McGovern, who have been playing really good footy," he said.

Brown said North had played some top teams over the past few weeks and had shown improvement, even though they had not won.

"I think we can take some confidence from that and our previous finals experience helps as well," he said.

Brown said it was hard to imagine how he would feel when the next pre-season rolls around and Petrie, Dal Santo, Firrito and Petrie do not turn up at Arden Street.

"I've been around these older guys a lot and I've been able to take in what I can and try to fit into the team dynamic," he said.

"It might be that some of the younger guys have to take more of a bigger role.

"We're just focusing on trying to get through the Adelaide game and trying to win for those guys."