When Michael Hartley signed a New South Wales scholarship with Collingwood at 15, he thought he was destined to become football's "next big thing". 

But the smooth path Hartley envisaged would carry him to AFL stardom was littered with hidden bumps, potholes and off-road detours.

Finally, seven long years later, Hartley made his AFL debut last Saturday for Essendon. 

The key defender's first game had a touch of fairy tale: he teamed well with fellow backmen James Gwilt and Matt Dea to subdue Melbourne tall forwards Jesse Hogan, Jack Watts and Cameron Pedersen; he bombed a goal from 55m late in the second quarter; and he enjoyed a stirring victory with a club some thought might go through the season winless. 

But Hartley's journey to his dream debut was, at times, a nightmare.

"As soon as I got the New South Wales scholarship, I thought 'I'm set for life, I'm going to be an AFL superstar'. I thought I was the next big thing," Hartley told AFL.com.au this week. 

"Then I got drafted by Collingwood (in the 2012 rookie draft) and things just started to go wrong from there."

Hartley enjoyed a good first pre-season at Collingwood, and at the end of it was rewarded with four NAB Cup games.

But he played just four more games in 2012 with Collingwood's VFL team before a shoulder dislocation ended his season.

It was the start of a horror run of shoulder injuries that would see Hartley play just two more VFL games (one was a practice match) over the next 18 months. 

During that time, he had five operations – three on his right shoulder and two on his left – before he finally regained some confidence in both joints.

Unfortunately, by that time, Collingwood's patience had run out – understandably, Hartley says – and the key defender was delisted at the end of 2013.

Hartley briefly toyed with pursuing a career as a punter in America's NFL, but a conversation with his father, Colin, convinced him not to give up on football. 

"Dad said, 'You're still just a kid, there are still plenty of opportunities, you've just got to stick it out in Melbourne and have another crack'," Hartley said.

"So it went from there because of Dad really. He's an absolute ripper."

Hartley decided the best place to reignite his football career was at a stand-alone VFL team that wasn't committed to fielding a host of AFL players each week.

He settled on Coburg, which at the time had recently dissolved its affiliation with Richmond.

That decision made, Hartley then had to find a job to supplement his VFL wage. Over the next two years, he worked as a waiter, labourer and hospital storeman.

At Coburg under coach Peter German, Hartley enjoyed a strong 2014 season that earned him an invite to that year's Victorian draft combine but – in another setback – not a spot on an AFL list.

Disappointed but not disheartened, Hartley simply resolved to get better. 

Adopting a more attacking approach in 2015, he took more intercept marks and ran off his man whenever possible, while still maintaining the defensive side of his game.

At the end of the year, he shared Coburg's best and fairest award, was named in the VFL team of the year and, most importantly, was taken by Essendon at pick No.68 in the national draft.

And last Saturday he finally became a fully-fledged AFL player.

Fittingly, his father was there to see his debut, having travelled from Penrith in Sydney's western suburbs.

That was nothing new for Colin, who together with his wife, Bonny, made the nine-hour drive down to Melbourne nearly every week for two years to watch Hartley at Coburg.

Last Saturday, he flew down, courtesy of the Bombers. Unfortunately, Bonny could not make it, as Hartley's debut clashed with his younger sister Allison's 21st birthday.

Elder brothers Nick, 27, and Chris, 25, also had to remain in Sydney for work.

Nonetheless, it was a special day for father and son to share.

For Colin, there were several highlights. Seeing Michael presented with his jumper in the rooms before the game. His first touch. His first goal. And the win.

"The way the players got around Michael after his goal was something I won't forget … what a great day," Colin said.

Hartley won't forget walking out on to the MCG and indulging in a "quick spin" to take in the crowd.

"It was just awesome looking up at the big coliseum," Hartley said.

"I looked back at Joe Daniher. He was just behind me and he gave me a smile."

Standing in the middle of the players' circle as the Dons belted out 'See the Bombers fly up' after the game, Hartley was sprayed with so much Powerade he couldn't see. 

He couldn't have cared less.

"Everyone was screaming, all the fans and the families, all the support staff," he said. 

"There were just smiles on all the faces and it was awesome to be a part of it."

Hartley's goal now is simple. He wants to play another senior game. Then another. And then another.

To do so, he knows he can't afford to get ahead of himself.

The way he celebrated his debut suggests there's little chance of that.

Shortly after leaving the Bombers' rooms last Saturday evening, Hartley attended Coburg's 2016 season launch, keen to give back to his former club. 

"I don't know how many people would bother doing that after their first game of AFL, but Michael chose to do that. That's the type of person he is," Colin said.

"He was a bit tired, but this was the club that helped him get back into the AFL and he wanted to be there."