It’s a case of what could’ve been for the Socceroos as Aussie coach Ange Postecoglou continues to make waves in Europe, with the manager drawing high praise from Real Madrid boss Carlo Ancelotti ahead of their teams’ Champions League clash.

The 57-year-old parted ways with the Socceroos in 2017 despite guiding the side to the 2018 World Cup, saying at the time he was ‘disillusioned’ after Australia’s 2015 Asian Cup triumph did not have the long-lasting impact he thought it would.

Fast forward five years, and Postecoglou has a J-League championship under his belt and is the first Australian manager to win a European title after he led Celtic to the top of the Scottish Premier League last season.

Despite his appointment at Celtic being widely laughed at in June 2021, Postecoglou has transformed the side into a take-no-prisoners, ruthless attacking machine – and it has caught the eye of Ancelotti.

Celtic and Real Madrid are set to clash in the first match day of the Champions League season at 5am Wednesday (AEST), and Ancelotti said he knows his side will need to be up for the fight.

‘They play very intense. They have had a great start to the season, there will be a great atmosphere in their stadium,’ he told Spanish publication Marca.

‘We’ve got the most difficult game of this first half of the season. We’re going to be up against a team playing great football and we have to be ready.’

It’s high praise from the boss of one of world football’s biggest clubs, and the Aussie said going up against the might of Real Madrid was ‘why you want to be at this [Celtic] football club’.

It will be the first time the two clubs have clashed in competition in 40 years, but Postecoglou said his side won’t die wondering.

‘If we’re not successful, fair enough, but let’s go down swinging, rather than deferring to someone because they’re a good team,’ he told the Sunday Post.

‘You want to measure and test yourself against the best and that’s what we’re going to do. They’re the best and we’ll test ourselves.

‘What a great opportunity to play our football. Our supporters want us to take the game to Real Madrid, and see where it takes us. Let’s have a crack anyway.’

‘He’s (Postecoglou) drilled into us from day one the way he wants to play and that won’t change for anybody,’ Turnbull told the Scottish Sun.

‘We will go into the game full of confidence and try to play our own game … We don’t want to sit back against any team.

‘Whether it works or it doesn’t, we will stay play that way and, hopefully, it does work.’

Postecoglou will become the first Aussie to manage in the Champions League come kickoff, but for former Socceroos star and A-League coach Kevin Muscat, it’s just a reminder of ‘what could’ve been’ for the national side.