Forward Drew Petrie says Ben Brown is close to "a lock" in North’s squad after his performance against the Brisbane Lions and believes the forward line can function effectively with three talls.

Jarrad Waite led the way in attack against the Lions last Sunday, registering an equal career-high of seven goals from 22 touches and 12 marks.

Fellow tall Brown booted three goals in his first appearance of the season, while Robbie Nahas (one goal) and Mason Wood also played their first games.

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Petrie said sharing the load in attack with fellow big men Waite and Brown added another point of difference.

"The three of us were able to move around the forward line and not one of us stayed deep all game and not one of us (was) relied upon to get up across the wings," Petrie told SEN’s Morning Glory on Tuesday.

"(Waite’s) going to demand a really good defender each week and with Ben Brown improving the way he is … he’s probably just about a lock now for us.

"The synergy of the forward line worked a lot better (against the Lions) versus when we played Adelaide, (when) we had a few midfielders and guys that aren’t so regular in the forward line playing as a forward."

PRESS PLAY above to listen to the Petrie interview.

Petrie acknowledged the club will face a tough month, with matches against Port Adelaide, Geelong, Hawthorn and Richmond.

"We’re certainly understanding of where we are," Petrie said.

"We did what we should’ve on the weekend against Brisbane; they were a little bit undermanned and a little bit off … we’re not getting carried away with that result.

"Judge us after that next little four or five-week block."