The Australian told the crowd at Parkhead, who watched Celtic lift the Premiership trophy after thrashing Motherwell 6-0 on Saturday, that they were "the best fans on the planet".

And after his first season, in which he'd also masterminded a League Cup triumph, Postecoglou suggested it was just the start of the adventure.

"You've embraced me, embraced my family, embraced this jumper," the former Socceroos boss told them, as his wife and children joined him on the pitch for the trophy-lifting celebrations.

"I want everyone to enjoy today, enjoy the summer and we'll come back bigger and better, because we never stop!"

Celtic, who'd confirmed their 10th title win in 11 seasons last Wednesday night at Dundee United, celebrated with a thumping win over Motherwell, with Socceroo Tom Rogic bowing out from the club in his final game after nine distinguished years.

Postecoglou was soaking it all in and urged his players to do the same.

"I have learned along the way that you need to take it in and enjoy it," he told reporters later.

"Most managers are no different. We are always thinking about the next step but I have to stop and celebrate what this group of people have achieved.

"That's why you do it - you do it for days like this.

"Let's not kid ourselves. When we roll up for the first game next season, our supporters will expect us to play football a certain way, win and be successful.

"We have to be ready for that. That's our responsibility while we're at Celtic. And it's the way I'm built. This was the first stage.

"We've put in place a really strong foundation and have overcome a lot of obstacles.

"But being champions gives you a little bit more belief. They've already climbed the mountain so they know they can do it.

"It's about allowing them to enjoy it. But if they want this feeling again, they'll need to come back better."

Australian Associated Press