The transformation of Matildas goalkeeper Mackenzie Arnold - ESPN

It is the final game of Group B at the 2023 Women's World Cup.

Australia is in a must-win match against Olympic champions Canada and, while the tournament co-hosts are ahead, momentum is slowly starting to shift in the North Americans' favour.

Canada flyer Deanne Rose shapes up to take a shot. She only has to place the ball beyond Matildas keeper Mackenzie Arnold and the match will once again be in the balance. Her shot is low, aiming for the corner of the far post. But Arnold makes the save, unconventionally with her feet, and Australia maintains their clean sheet.

It was a small moment, particularly in what would go on to be a resounding 4-0 victory for the Matildas, but it spoke volumes to the growth of Arnold as a goalkeeper. This time last year, the West Ham United shot-stopper was widely considered in Australia's top three keepers — but few had her pegged as the Matildas No. 1.

In a way, Arnold had made a national team career out of being the backup. She'd gone to two World Cups, two Olympics and two Asian Cups. In those three tournaments, she has made zero appearances, one appearance, and three appearances respectively. For whatever reason, Arnold had always been a good player, but couldn't translate her club form to the national team.

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That all changed at the start of 2023 when she started every game at the Cup of Nations and would go on to be named player of the tournament. Subsequently, Arnold started for Australia in friendlies against Scotland and England, keeping a clean sheet against the reigning European champions. All of a sudden, heading into a World Cup on home soil, there had been a seismic shift in the Matildas keeping ranks. The Gold Coast-born