Brad Scott and his coaching team had told Harper "1000 times" before that they didn't care if he got pinged in a tackle provided he was taking opposition teams on with his speed.
Brent Harvey had worked closely with Harper this year, often studying his match vision with Werribee and identifying moments when he could have taken the game on.
Harvey's message to Harper had been simple – if he backed himself, he would only get caught one out of every 10 times he took off with the ball.
But Harper has struggled to act on that advice in the season and a half that he has been out of North's senior team.
He couldn't help feeling he was letting his teammates down every time he got pinged for holding the ball.
But when he gave away a free kick after an ill-fated run for Werribee, Harper reacted the way Scott and Harvey had long wanted him to.
"There's a fine line between taking the game on and giving it to the best option, but I'm slowly working on it," Harper told AFL.com.au this week.
"A couple of times in the past few weeks, I've taken the game on and the one time when I got caught it was one of the best feelings that I've had.
"I didn't care because I thought, 'Look, it's OK, I took the game on' and it was just a good feeling that I was using my speed'."
Roos fans were treated to regular sightings of Harper in full flight during his first two seasons at Arden Street.
The No.27 pick in the 2010 national draft, Harper played 37 games in 2011 and 2012 and, along with fellow 2010 draftee Shaun Atley, gave North, widely seen then as heavy on grunt and short on class and pace, an exciting new look.
As expected, Atley has continued to develop as a counter-attacking backman in the past two seasons, and has not missed a game.
But the similarly high hopes North held for Harper so far have not been met.
Quiet in the opening three rounds of last season, he was dropped and has not played a senior game since.
Harper's subsequent form in the VFL hasn’t demanded a senior recall.
He has shown trademark flashes of brilliance, but has not put together the consistent stretch of good form that would force North's hand at the selection table.
In fairness, he has struggled with an ankle injury. It required an operation in October last year and another in late January, which severely interrupted Harper's 2014 pre-season.
But when asked what was holding his football back at the moment, Harper did not use injury as an alibi, pinning most of the blame on a simple lack of confidence.
Desperate to improve the mental side of his game, Harper has been working regularly with a sports psychologist this season.
In their sessions, it soon became apparent Harper's confidence problem stemmed from issues beyond the football field.
"I went in there thinking I need confidence in my footy, but he (the psychologist) said it comes off the back of the other parts of your life," Harper said.
"He said, 'You're not really confident in everything else so you need to work on your life outside football to become more confident.'"
One of the main challenges Harper subsequently set for himself was to knock on the doors of Scott and the rest of North's coaches to seek feedback on his game and senior selection prospects.
It sounds a simple task.
But Harper had always been a quiet, non-confrontational person, who was content to "sit back and take things as they come".
His new challenge has taken him out of his comfort zone.
He is now a regular visitor to the offices of North's development coaches, Gavin Brown, Ben Dyer and Jarred Moore, and will knock on Scott's door from time to time to check how far he is from a senior recall.
Harper is also trying to speak up more at team meetings, and even to occasionally challenge his coaches when they're discussing his game vision, rather just accepting their take on his performance.
Contracted to the end of the 2015 season, Harper is determined to fulfill his football potential.
"It was pretty hard for me at the start to do it, but I've been told by so many people that you've almost got to be a pest around the club to keep your name up in lights, so they don't forget you," Harper says.
"At the end of the day, when the club has to delist people, they're going to pick the person who looks like they're not having a crack.
"So you want to be looking like you're a least trying to get the best out of yourself."
Harper says his "really slow start" to 2014 frustrated both him and North's coaches, but feels he is slowly starting to produce some consistent VFL performances.
The 22-year-old says the three on-field things he is focused on are winning more of the ball – he is working closely with Gavin Brown on this – defensive efforts and fitness.
Harper says his ankle still requires constant physio because of his tendency to produce more scar tissue than normal, but is "almost there" and should allow him to embark on a full 2015 pre-season.
But before that Harper is focused on having a strong finish to 2014 and has not given up on a senior recall.
"Hopefully soon I can get back in there," he says.
