Postecoglou was sacked by Spurs last June despite leading them to Europa League glory over Manchester United, the club's first major trophy for 17 years. 

Indeed, the Australian became the first Premier League manager to win a major trophy and be sacked at the end of that season since Antonio Conte in 2017-2018 with Chelsea.

His successor, Thomas Frank, has since been relieved of his duties after an eight-game winless run in the Premier League (D4 L4), leaving Spurs 16th in the table. 

Postecoglou, who guided Spurs to a fifth-place finish in 2023-2024, feels the club is lacking real ambition.

He pointed to its signings in the summer of 2024, with Dominic Solanke joined by a trio of unproven youngsters in Lucas Bergvall, Archie Gray and Wilson Odobert.

"They've got an unbelievable stadium and training facilities, but when you look at the expenditure, particularly on wages, they're not a big club. I saw that," Postecoglou said on The Overlap.

"When we tried to sign players, we weren't in the market for those players.

"At the end of my first year, when we finished fifth, how do you then go to really challenging? We had to sign Premier League-ready players.

"We signed Dominic Solanke, who we were really keen on, and three teenagers. I was looking at Pedro Neto, Bryan Mbeumo, Antoine Semenyo, Marc Guehi.

"If we're going to go from fifth to there, then that's what we needed.

"Those teenagers are exciting players, and they'll be brilliant for Tottenham, but they're not going to get you from fifth to fourth or third.

"But what was coming from the club was we're a club to compete on all fronts."

That failure to bring in established Premier League players saw Spurs finish 17th with just 38 points, their lowest top-flight finish in 48 years since the 1976-1977 season.

Things failed to improve under Frank, despite the Dane ensuring Spurs reached the last 16 of the Champions League.

Frank averaged 1.12 points-per-game as Tottenham boss in the Premier League (29 points in 26 games), the lowest rate of any Spurs manager to take charge of at least five games in the competition.

Although Postecoglou felt it was the right decision for Spurs to part ways with Frank, he sympathised with his successor, given the departure of senior figures at the club's hierarchy, most notably Daniel Levy. 

"It's a curious club, Tottenham," Postecoglou said. "They made a major pivot last year, not just with me but with Daniel [Levy] leaving as well. It's created an environment of uncertainty. 

"They've had world class managers there before and they've not had success. So for what reason is such a major pivot?

"Thomas has walked in – what's the club's objective? Compete on all fronts? The club hasn't competed on all fronts for a very long time, and the most influential person at the club for the past 20 years is also going.

"If you're going to do such a major pivot, you've got to understand there's going to be some instability there. Did Thomas know he was walking into that?

"And it's a fair departure from me. Anyone who studies the game will know it wasn't like it was a progression from me. I built that squad to play a certain way over the past couple of years. It's a curious club.

"There isn't really a common thread of what they're trying to do. I think part of Tottenham's DNA, for want of a better word, is that they do like their team to play a certain way."