North Melbourne coach Brad Scott says Sunday's loss to the Cats was a vital learning experience for the club's emerging players.
The Roos largely outplayed Geelong for three quarters – taking a 25-point margin into the last change and leading by as many as 32 – but conceded five goals to one in the fourth term.
"We're trying to build a style that's going to potentially leave us vulnerable at times, because the ability to sustain our effort is going to be a challenge," Scott said.
"What we need to do is understand we have really good, athletic young players and they have terrific endurance. We've recruited around that pretty strongly.
"But one thing I know is when you're 18, it doesn’t matter how athletic and how good an endurance you've got.
"This is a brutal game and they don't have the resilience yet to sustain the effort for long enough."
Scott highlighted retired defender Michael Firrito as a player who was running as hard at the end of matches as the start, owing to the toughness and "strength of character".
Veterans Harvey (432 games), Firrito (275), Nick Dal Santo (322), Drew Petrie (317) and Daniel Wells (243) all departed the Kangaroos at the end of last season.
Further experience was lost when All Australian ruckman Todd Goldstein (ankle) was a late withdrawal, but Scott hailed his replacement Braydon Preuss's performance.
Preuss had 13 disposals, won 46 of North Melbourne's 54 hit-outs – against Geelong's total of 21 – set up multiple goals and was a genuine physical presence in his second match.
It was an eventful game for the ex-Queenslander, who was reported for rough conduct in the second quarter and gave away the free kick that led to George Horlin-Smith's match-winner.
"I thought Braydon Preuss emerged today," Scott said.
"People probably thought through the JLT series that he emerged, but this is a different game, the AFL regular season.
"He got his hand to the ball really well. I think we were roughly plus-33 or something in hit-outs and minus-three in first possession, so you put that down to a little bit of synergy with Preussy.
"Our inside mids haven't played a lot of footy with Preussy, or do you put it down to (Joel) Selwood and (Patrick) Dangerfield reading the ball pretty much as well as anyone."
Scott did not rule out Preuss remaining in the side alongside Majak Daw and if, as expected, Goldstein returns against Greater Western Sydney next week.
"We're just going to pick the best team we think lines up against the opposition each week, also with a view to what our long term looks like," he said.
"We'll keep working with those guys (and) make them multi-positional."
Trent Dumont, who shadowed Dangerfield for most of the day, also impressed Scott, as did best-on-ground midfielder Shaun Higgins, and his players' tackling numbers.
The Roos won the tackle count 33-12 in the opening half and finished with a 65-47 buffer.
