Maddison's support for and defence of the beleaguered Tottenham manager on the eve of the semi-final first leg at home to Norwegian champs Bodo/Glimt was striking in its passionate tone.
Postecoglou needs all the help he can get, presiding over a team lying 16th in the Premier League and reported heavily to be on his way out even if Spurs lose their European last-four tie against the Scandinavians, the tournament's romantic underdogs.
But on Wednesday, Maddison made it sound as if the 59-year-old still hasn't lost any backing from his struggling team, who've just come off a 5-1 league drubbing at new champs Liverpool.
Adamant the season can still be a huge success if they can end a 17-year silverware drought and earn Spurs a place in the Champions League next season, Maddison insisted: "We're behind the manager, 100 per cent. I think he's a great man.
"He's the first person to tell you - I've heard it myself - that we've had a poor season, especially in the league. We've been very good in Europe, but the league season's probably been unacceptable, and we can all take a collective responsibility for that.
"We definitely want to reward the fans for the support that they give us by creating something special because the league hasn't been good enough, definitely, but it hurts us as well.
"It hurts me a lot that we're having a poor season, but this is why we're so motivated for this competition because the season can still be so special.
"No-one in the whole club from top to bottom can be satisfied with where we are. It definitely hurts.
"I had to do an interview at Liverpool on Sunday and we have lost 5-1. I'm a bit embarrassed myself, and you have to go and talk."
Spurs are heavy favourites against the Norwegian champions from the little fishing town of Bodo, just north of the Arctic Circle, who beat Postecoglou's Celtic home and away in the 2022 Europa League.
"You'd love us to think that — that you're a small club and we don't rate you," Postecoglou chuckled to a Norwegian journalist, who reflected on the disparity in resources between the two outfits.
"Bodo's there on merit. They beat Lazio, they beat Olympiacos, tough teams. They're there because they're a good football team," Postecoglou said.
Still, despite all Spurs' struggles, it would be a shock for them to lose as it's hard to get away from the thought of how Tottenham are watched at home by 63,000 while Bodo's entire population is 55,000.
As for the Europa League being a prize that's no big deal, Postecoglou was adamant: "People are always trying to diminish it. I've heard people say it's the equivalent of Man United winning the FA Cup - no it ain't, I'm sorry, not on any planet.
"What's ahead of us is an unbelievable opportunity. We have generations of fans who want this more than anything else, to share with the people they love, a special moment supporting their football club."
