The new Spurs boss prepares to host Klopp's Liverpool team on Saturday, aiming to extend a promising unbeaten run which has seen them take 14 points from their opening six league games.
Klopp is in the middle of his own rebuild as he seeks to recapture the heights of his seven-year spell at Anfield, during which Liverpool won the Champions League -- beating Spurs in the 2019 final -- and the Premier League in 2020.
Speaking in a news conference on Friday, Postecoglou said: "Jurgen is an outstanding manager, he's one the managers I think it's fair to say who has made an impact on the competition, not just his club. Because when he came in, with the way Liverpool went about things, he challenged quite a few of the conventions about the Premier League and introduced a new style of play that others have followed. It's a great test for where we are at the moment in terms of our development.
"From when Jurgen came to the league and the way they set up, just the tempo and intensity with which they played. Both offensively and defensively, it was at another level.
"The Premier League has always been a fairly high tempo league but I thought they took it to another level. At times, it looked almost chaotic but you could see there was a plan behind it. It is very hard to cope with."
Postecoglou, born in Greece but raised in Australia, played down his boyhood support for Liverpool, adding: "It was the '70s, so you went one of two ways: it seemed they only used to show Liverpool or Man U [on television in Australia] at the time so a couple of my best mates went Man U, so I went the other way so we could keep it interesting.
"Like any kid, I had the posters up on my wall, so Liverpool was my team. But you grow up, things change. I used to love Happy Days back then too, but I don't have pictures of The Fonz on my wall today either. So it's just the way things are."
Spurs are hopeful of having James Maddison and Son Heung-Min available after the pair trained despite picking up knocks in last Sunday's 2-2 draw at Arsenal. Winger Brennan Johnson will miss out due to a hamstring problem.