This article has been updated since it was first published on May 31, 2021
A headline in The Scotsman posed the same query late last month when it reported that the attack-minded coach was leading the odds to take charge of the Glasgow giants after top candidate Eddie Howe -- who had been expected to sign a contract within days -- turned down the opportunity.
While players such as Mark Viduka, Scott McDonald and Tom Rogic have helped form a long and proud Oz-Caledonian history at Parkhead, the appointment of 55-year-old Postecoglou represents a significantly left-field move by the club.
Despite his reputation in Australia and across Asia, the Athens-born coach -- who migrated to Melbourne as a five-year-old -- represents an almost complete unknown in European club football; his lone stint on the continent was a brief stint in charge of then-third-tier Greek side Panachaiki back in 2008. Hoops' fans, though, shouldn't expect Postecoglou to be overawed by the occasion should he emerge as their coach. In fact, he'd prefer to earn their respect.
"Being Australian, I sometimes feel I'll never walk into a dressing room and get that instant credibility because of where I'm from," he told ESPN's Gabriele Marcotti in 2016. "But that's fine. Even in Australia, where I've had success, I never assumed that people would follow me because of who I am. I knew that I'd get buy-in if I could provide clarity, if I could put the right picture in people's minds. I've been able to do that. It doesn't scare me. It's who I am."
Indeed, looking beyond that brief stint in the Greek lower leagues, Postecoglou's unwavering self-belief has helped forge one of the most consistently successful careers of any contemporary coach outside Europe. A two-time Australian national champion as a player with boyhood club South Melbourne -- the second title delivered under the guidance of the legendary Ferenc Puskas -- he took charge at his beloved Hellas after retirement and led them to back-to-back championships.
"We were a young group, but he instilled a fearlessness in us," Postecoglou told ESPN about life under Puskas, who has his own statue on Melbourne's Olympic precinct. "We weren't afraid to lose or make mistakes. He just wanted us to love the game, enjoy the game, and that is something I've taken into my football."
Coaching Australia's junior national sides for the next half-decade, failure to qualify for the 2007 Under-20 World Cup led to his ousting and reflective spell in Greece before, in 2009, he took over at A-League side Brisbane Roar and established himself as Australia's premier coach. At one point going on a 36-game undefeated run, his side's adoption to a fearless, possession-based and attacking style of football earned it the nickname "Roar-celona" and two consecutive A-League titles. A return to his hometown to take over Australia's biggest club, Melbourne Victory, followed.
In 2013, Postecoglou was poached to take over a Socceroos reeling from back-to-back 6-0 losses against Brazil and France. Official histories would simply note that Australia subsequently lost its three games at the 2014 World Cup against Chile, Netherlands and Spain but fail to paint a proper picture of what transpired in Brazil. Down 2-0 early against the Chileans in their first game, an inexperienced Socceroos side cut the deficit to one and had a goal disallowed before conceding late to go down 3-1. They then raced to a 2-1 lead and should have made it 3-1 over the Dutch, who were coming off a 5-1 win over Spain, before substitute Memphis Depay inspired his side to a 3-2 win.
The following January, he was in charge as Australia achieved its greatest achievement at international level: defeating South Korea in the 2015 Asian Cup final to lift the trophy on home soil. Just as much a footballing evangelist as supreme motivator, Postecoglou's international success was built around a desire to instill a confidence and belief not just in the playing group, but within Australian football as a whole.
Battling internal and external perceptions that Australian teams were forever doomed to engage in displays of battling pragmatism against their footballing betters, he preached a belief in an attacking, fearless and never-say-die style of football that he felt better represented the nation's sporting psyche. He didn't just want Australian sides to deliver scares to the likes of Chile or Netherlands -- he wanted it to reach a point where they would consistently beat them. Should he land at Celtic, he would assuredly adopt this same mindset at the prospect of potential meetings with the likes of Manchester City, Barcelona or Bayern Munich.
Critically for Postecoglou, this style of football -- one that empowers the "artists" -- is one that his father Jim, his hero, would have wanted to watch. "My father passed away a couple of years ago," Postecoglou told Hudl in 2020. "When my team is playing, I pretend my father is in the grandstand and think, 'would he be enjoying watching this team?' And that's always been at the root of everything I have done."
Postecoglou's unwavering commitment to his principles -- or stubbornness, as others might put it -- and a desire to return to club football led to his resignation from the Australia post after securing qualification for the 2018 World Cup via a playoff win over Honduras in November 2017. He had increasingly clashed with segments of the Australian game who took issue with his devotion to reshaping the nation's footballing character even as his side spluttered on its way to Russia, and he grew frustrated with a perceived lack of support from the Australian federation.
He reappeared at J1 League side Yokohama F. Marinos a month later. Yokohama finished 12th in his first season, scoring the second-most goals in the league and conceding the third-most -- but that initial bedding-in period quickly made way for the vindication of his ethos. In his second year an all-or-nothing, highly entertaining style of play led Yokohama to its first Japanese crown in 15 years. It also gave him a City Football Group link with Fergal Harkin, the favourite for the director of football vacancy at Celtic.
That template, a period of integration followed by success, has generally been the model that Postecoglou has followed throughout his career: his titles with South, Roar and Yokohama all arriving in his second year in charge. But coming off a campaign where their quest for the fabled "Ten in a Row" was foiled by rivals Rangers, whether Celtic has the patience for a new boss to implement his preferred style is perhaps the biggest question mark hanging over the potential appointment. History suggests that the Australian would deliver success relatively soon, especially with the calibre of players that Celtic are able to attract compared to the rest of the Scottish league. But will it be soon enough?
If Postecoglou thought the media scrutiny as Socceroos boss was grating, it will be nothing compared to the pressure cooker that awaits in Scotland. After watching their grip on Scottish supremacy slip, Celtic fans will be in no mood to suffer through any kind of extensive rebuild that allows Rangers to go unchallenged. Fall a few games back and the scrutiny -- which will already be heightened due to his outsider status -- will be crushing.
In the dressing room, fans shouldn't expect a wave of Australians to appear alongside Rogic in the playing ranks as Postecoglou sets about trying to stage the turnaround: not a single Australian arrived at Yokohama during his tenure. The same cannot be said, however, for Australian coaches. Postecoglou added long-time collaborators Peter Cklamovski and Arthur Papas to his staff when he landed in Japan in late 2017 and replaced them with Australian-born Malta international John Hutchinson and Shaun Ontong when the former pair parlayed Yokohama's success into coaching jobs of their own. Intriguingly, it was announced early Saturday that Papas was departing J3 side Kagoshima United FC due to personal reasons.
Ultimately, Postecoglou's move to Glasgow carries seismic repercussions for multiple fan bases. For Celtic, the Australian has been entrusted with quickly sending Steven Gerrard and Rangers back into second place on the Scottish hierarchy and returning the Bhoys to some semblance of European success. Celtic is not a project -- you must win now. But it's a club job that is also, without question, the biggest an Australian coach would have ever been entrusted with.
Success for Postecoglou would bring with it a chance to break down barriers of perception and create a new narrative not just for himself, but for all Australian coaches in Europe.