Brendan Rodgers returned to Celtic for a second stint as manager determined to restore the club's battered reputation on the European stage and make a personal impact on the Champions League for the first time.
Just over 18 months later, Bayern Munich visit Glasgow on Wednesday in the Champions League play-off round, giving Rodgers and the Scottish champions a chance to shock the continent.
Celtic have been one of the big winners of the Champions League's revamp this season.
Despite an unprecedented era of domestic dominance, with 12 Scottish titles in the last 13 years, the Glasgow giants won just three Champions League games between the 2013/14 and 2023/24 seasons.
In the old format, European campaigns were routinely over for Celtic before Christmas after just six games against higher seeded opponents.
Rodgers' men may have benefitted from a kind draw against the likes of Slovan Bratislava, Young Boys, Dinamo Zagreb and Club Brugge in the first year of the eight-game league phase.
Brendan Rodgers: "I don’t have any doubt that we can hurt Bayern. We’ve got goals in us, we’ve shown that at all levels. We can score goals. They’ve obviously got threats but it’s the knock-out stages of the Champions League. Every team has big quality and I’ve been up against… pic.twitter.com/v2wNfJmhE2
— Bayern & Germany (@iMiaSanMia) February 10, 2025
But they took full advantage, losing just twice at Borussia Dortmund and Aston Villa, to qualify for the knockout stage of the Champions League for the first time in 12 years.
That breakthrough was particularly sweet for Rodgers.
The Northern Irishman hoovered up seven trophies in his first spell at Celtic before an acrimonious departure for Leicester in 2019.
But he had won just three of his first 24 Champions League games across four campaigns as Liverpool and Celtic boss.
"The one glaring thing from my first time here was doing better in Europe," said Rodgers.
Along the way there some scarring experiences. His decline at Liverpool began in 2014 by failing to get out of a group including Basle and Ludogorets Razgrad.
🍀 @CelticFC manager Brendan Rodgers on Dane Murray's development and how he earned his spot in a rotated lineup today
— Premier Sports (@PremSportsTV) February 8, 2025
"He's someone I've liked....really talented young player." 🗣️#ScottishCup pic.twitter.com/ZDTCPkggdq
Celtic conceded seven to a Lionel Messi-inspired Barcelona in 2016 and Neymar's Paris Saint-Germain a year later.
There was even a 7-1 humiliation in Dortmund earlier this season.
But this time Celtic bounced back with a five-game unbeaten run to forge a path into the play-off round, including a statement 3-1 win over RB Leipzig.
BAYERN'S RELIEF
"This is the highest level of club football, where there are top players in every team, but for us we've built through it and played some great football and showed different ways to win as well," Rodgers said.
"When we've had to dig in, we've been able to do that.
"Defensively we've been good at the level bar one game, so overall, there has been a lot of progress and I'm really pleased with that."
Now comes the acid test of how far the Hoops have developed when it comes to competing with Europe's best.
Despite a few bumps in their own Champions League road under Vincent Kompany this season, Bayern have the final of the competition in their own stadium on 31 May in their sights and are well on course to regain the Bundesliga title.
There were sighs of relief in Bavaria when the draw paired Bayern with Celtic instead of a return to Manchester City for Kompany.
On paper there should be no contest. Bayern's €950 million ($981 million, £791 million) revenue was €800 million more than Celtic's.
The German giants routinely spend more on individual players than the £36 million that the entire Scottish top-flight receives in television revenue in each season.
Celtic have also been weakened since sealing progress with the departure of star striker Kyogo Furuhashi to Rennes in the January transfer window.
But with the daunting task comes a great opportunity for Rodgers to banish the ghosts of his past on the Champions League stage.
"That's my job," he replied when asked how he will make his players believe they can beat Bayern are beatable in the Champions League cauldron at Celtic Park.