Everything about Mason Cox is big.

But his seismic efforts in Collingwood's 2018 preliminary final win over Richmond changed perceptions and might yet pave the way for more international converts.

In his 43rd AFL game, and only four years after first picking up a Sherrin, Cox turned the fortunes of a crucial final with a stunning display in the air and on the ground.

In the process, the American big man helped the Magpies book a Grand Final appearance in front of a stunned of 94,959 fans at the MCG, upsetting the premiership favourites.

His stats were ultra-impressive - 15 disposals, 11 contested possessions, 11 marks, 3.1 and almost 90 per cent game time.

Eight of those marks were contested, which was the second most in finals history, behind Chad Cornes' 2002 semi-final record.

Incredibly, Cox also had 403 metres gained that night, fifth overall for the Pies - not bad for a man standing 211cm.

But even those figures hardly did justice to how damaging Cox was for his team on that Friday night in 2018 where the Magpies knocked off Tigers for the first time in a final since 1937.

Nor do they detail the almost surreal moment where a Collingwood crowd found itself chanting "USA, USA" as Cox produced the greatest game of his AFL career.

“I really don’t understand it,” Cox said after the game. "I am an ordinary person in extraordinary circumstances … that’s the best way to say it. There were two USA flags (in the crowd) and a couple of USA chants. Every time I hear that I kind of laugh.

“I mean, c’mon, four years ago would you have ever pictured someone chanting USA (at an AFL game), or something like that’? It’s pretty cool and another part of the whole journey.”

Mason Cox celebrates a goal during the Pies' big preliminary final win over Richmond in 2018

Cox's journey at Collingwood officially began as a rookie draft international selection in 2015, but he was already an important part of the team structure by the preliminary final three years later.

His parents, Phil and Jay, watched his second final - the 2018 semi-final win over GWS - in their pyjamas from the family home near Dallas. Their son had had 11 touches in that game, and hadn't kicked a goal, but was better than in his first final against West Coast, when some called for him to be dropped.

In the excitement of the moment, they immediately booked airline tickets to Melbourne.

Twenty six hours after leaving their home bound for the preliminary final and arriving in Melbourne, Cox's father predicted "It's going to be huge". No one could ever have imagined just how huge it would turn out to be.

The Magpies ambushed the Tigers in the opening term, kicking five goals to one, with Cox playing a role in helping to bring the ball to ground.

But it was what transpired in the second term was remarkable.

The forward/backup ruckman took three towering marks - and kicked three game-defining goals - in the space of 11 minutes in the second term.

His goals came at the two, five and 11-minutes marks, with the difference pushing out to 42 points, which was effectively game over.

His coach Nathan Buckley would say later: "Mason's strengths shone through ... (but) he wasn’t the lone ranger.” 

One of Cox’s hangers came over Richmond captain Trent Cotchin, with whom he engaged in a little bit of trash-talking.

"I didn’t know what he (Cotchin) said, I thought someone was asking for a handball receive from 35m,” Cox said. “He is a Brownlow Medallist and he has had a better career than I will ever have … I have so much respect for the Richmond guys.

“I love it when people talk a bit of trash because it just gives me more oomph."

The AFL’s national and international talent manager Kevin Sheehan, who had closely involved in getting the American to initially try out in Australia, immediately knew Cox had changed the goalposts.

"To put a stamp on a game like that, I can’t think of a more remarkable performance from a player who didn’t grow up with our code,” Sheehan said.

“He desperately gets to ground balls and pushes out four or five balls per game which seven footers just don’t do. And he is so disciplined in making sure he isn’t outmarked.

“From the moment in the 1987 Preliminary Final when Jimmy Stynes ran over the mark, to 31 years later when another import takes eight contested marks on the same stage, that is the evolution of the international experiment.

“Mason Cox has been laughed at, probably on the field and definitely in the media off the field, but he has a very thick skin which sees him get stronger and, more importantly, better.”

Cox would say his preliminary final performance was “a confidence-booster, definitely."

He would go on to play a solid game for the Magpies in the Grand Final the following week, kicking two goals, having nine disposals and taking seven marks in the club's heartbreaking loss.