Can Postecoglou rediscover old comforts in Glasgow?

Ange Postecoglou's boys came out of the traps quickly against Real Betis that night, two goals up and cruising before a half an hour was played.

The only thing that pierced the silence of the Seville crowd was the incredulous jubilation of the visiting Celtic support.

With an injury-affected team, this was their new manager's first group stage game in Europe - Europa League, September 2021 - and he was owning it, until he wasn't.

Tottenham fans might have a sense of how this story ends. Two-nil Celtic became 4-3 Betis.

That was the first such lightning strike of Postecoglou's time in football management in the UK. Last Sunday against Chelsea was another.

The Australian is now back in the place he called home, Glasgow. His launchpad to White Hart Lane. On Thursday, Spurs play Rangers in the Europa League at Ibrox.

The visitors sit 11th in the Premier League. With one win in seven, a split support, an apparent lack of Plan B in his approach, injuries, and a player - Cristian Romero - appearing to have a pop at the club for a lack of investment, Postecoglou could do with rediscovering his halcyon days in the city.

Back then, his carefree Celtic treated Rangers like a cat treats a mouse.

There is a world of difference between the Scottish Premiership and the Premier League, but Angeball unites them both. As a game plan, it remains a terrible beauty, a thing of exhilaration and exasperation depending on the day.

Postecoglou doesn't really do steady. He's a yo-yo in human form.

In 76 league games with Celtic he had as many 6-0 and 6-1 victories on his record as he had 1-0s (four of each).

At Tottenham, in his 53 league games, he's had six 4-0 or 4-1 wins and only one routine 1-0. Even then, there was turbulence, Yves Bissouma getting sent off after 45 minutes.

Postecoglou returns to Glasgow, not beleaguered but sufficiently bothered to take on a shouty fan after the recent loss to Bournemouth.

If he gets hollered at in Glasgow - and he will - it'll be coming from Rangers fans with bitter memories of the rubble he reduced them to in his time up north. Happier days for Ange, those. Simpler.

Postecoglou and the angst that goes with him belong to Spurs now, but Celtic fans still feel blessed for the time they had with him. He arrived when the team needed a total rebuild and he did it in quick order, winning trophies with largely thrilling football.

More than half of the Brendan Rodgers team that's making improvements in Europe right now were brought in by the Australian.

It's true that Postecoglou operated in a weird footballing climate in Scotland.

Celtic bombed out of the Europa League in his first season but then went on a 23-game unbeaten run on home fronts, so the fans were sated.

They got embarrassed 5-1 on aggregate by Bodo Glimt in the Conference League but went on to win the domestic league, so Postecoglou was lauded.

In his one shot at the Champions League, Postecoglou was unbending in his attacking mindset even when drawn against Real Madrid.

For half an hour in Glasgow, his team were absolutely outstanding against the Spanish giants. It was some of the best stuff delivered by Celtic in Europe for years. They lost 3-0. Then they lost 5-1 away.

Postecoglou was regularly pressed on the high energy, high risk, low compromise style he deployed but said he'd 'never move an inch, mate,' in the way he saw the game.

Celtic secured two points from 18 in the Champions League that season.

Domestic dominance was the safety net that trumped European failure. Spurs have no such latitude in the brutal terrain of the Premier League.

Celtic have moved on a little since Postecoglou's departure and have hit on a style of play that works better for them on the unforgiving fields of Europe.

But Postecoglou's return will have some fans pondering what might have been had he never received an offer to go south.

Would he have tweaked his natural instincts for the greater good, as Rodgers has done, or would Celtic still be trying to go toe-to-toe with all comers, as they did on his watch, with bad outcomes?

The answer can probably be found in what we're seeing from the boom and bust that is Spurs - good enough to put Aston Villa, Manchester City and Manchester United to the sword, but also soft enough to cough up goals and points late on in a list of matches they had control of.

As much as Celtic fans loved having him, there's probably an acceptance now that they needed to lose him to advance in Europe, the real testing ground of a team that has Scottish football sewn up.

Because it's Postecoglou and because it's Rangers, half of Glasgow will be white on Thursday. They will always appreciate him and support him, but in the new world Celtic seem to be moving into, the days of lamenting him are over.