Postecoglou spent two years in charge at Celtic Park between 2021 and 2023, leading the Scottish club to five trophies in what was a very successful spell for the Australian.
Despite this, in his appearance on The Overlap's Stick To Football podcast, he put to rest any suggestions of a second stint at Celtic who have been in a rut since his departure.
"I loved Celtic. What a football club. If I was younger, I probably would have stayed there longer for three or four years.
"I think I could have made progress with them in Europe. But at the time, it had taken me a lot of time to get to this space and the opportunity to join Tottenham was too good.
"In terms of going back, I don't go back. I don't think that's been my career.
"Whatever the next step is, I think it will be something new, something I can make an impact in, somewhere I can win things.
"It doesn't diminish the affection I have for Celtic. It was a great experience. For two years, to be within a community that is so passionate, and it's crazy how passionate they are, obviously I was fortunate enough to have success.
"It's a positive experience and I loved every minute of it. I look back on it fondly but… I won't go back. It's not how my career plays out."
He was Postecoglou was replaced by Brendan Rodgers in 2023, weeks after he secured a treble at Hampden Park over Inverness Caledonian Thistle.
Postecoglou is currently without a club after he was sacked by Nottingham Forest in October, a move he admits to regretting after winning none of his eight games in charge.