AMERICAN Mason Cox was almost laughing when Darcy Moore hit him on the chest inside 50 in the opening minutes of the Anzac Day clash.

The two mates, who began training together late in 2014, had joked about making such a moment happen if Cox's dream came true and he became the fourth American-born player to reach the AFL after Sydney Swan Sanford Wheeler, St Kilda's Jason Holmes and Tom Banks, who played eight games for Fitzroy in 1897.

Even moments before the ball was bounced one comment showed the pair understood the magnitude of what was about to take place.

Cox had told Moore: "It's a crazy life we have, hey."

Now the pair had taken the craziness to another level.

Cox was in the middle of the MCG with 85,000 people about to watch him kick a football he had not seen until he went to training camp in Los Angeles just two years earlier.

Cox battled to stop the mirth running through his body.

Moore closed his eyes.

The ball sailed through and Cox had a goal on the board.

Cox pointed to Moore, an action that has become the American's post-goal custom, before teammates swamped him.

"It was an unbelievable feeling and I'll never forget it," Moore told AFL.com.au.

"I couldn't have scripted it better."

That the two share Collingwood's forward line is unbelievable in itself.

Moore, the son of dual Brownlow medallist and former Collingwood captain Peter, joined the club under the father-son rule, one significant bow to tradition that remains in the game.

Cox, the son of a Texan engineer who played soccer as a kid before being a walk-up basketballer at Oklahoma State University while studying mechanical engineering, was put on the Magpies list as an international rookie, a rule that gives clubs an incentive to punt on a new-look future.

The pair started at the club early in the pre-season, becoming mates as they played VFL together before moving in with each other late last year.

Moore knew him so well he was given the honour of presenting Cox with his jumper pre-game despite having played just 13 games himself.

"I know how hard he has worked and how far he has come," Moore said.

"He has come a long way from running 60m at training with the ball without bouncing it."

Cox's brother Austin had come a long way to watch Mason play too, making a hasty trip from Seattle to be part of the occasion.

He jumped out of his seat when the mark was taken and could not believe it when the goal sailed through.

"Oh my god, it was insane," Austin Cox told AFL.com.au.

"It was definitely worth the trip."  

It was a thought echoed many times over in the Collingwood rooms as the 211cm Cox commanded attention alongside father Phillip, mum Jeanette and another brother Nolan.

Cox embraced Moore's father, who played 249 games for the Magpies and Melbourne, and copped a reminder from forwards coach Anthony Rocca, whose brother Saverio moved from the AFL to the NFL, to not get ahead of himself.

None of it seemed to faze the 25-year-old too much.

Moore described his mate as a free spirit, who is "really open and not afraid to look a challenge in the face and take it on."

That attitude has taken him from Oklahoma to LA to Melbourne, and the crazy ride will continue next week in WA when Collingwood plays West Coast.

"I'll ride the wave and wherever it lands, it lands," Cox said.