Though Spurs are heavy favourites to progress to the final, Postecoglou claimed his side should be wary of the threat Bodo/Glimt pose, particularly given their rapid rise over the last few years and prior experience of stepping up in Europe.
"I don't think [their progress] is surprising," Postecoglou said. "I obviously have history with Bodo, we played them when I was at Celtic and I scouted them pretty extensively for that game.
"I remember they beat Roma at home with Jose, and I remember Jose speaking about how difficult it was playing there. And I've followed them closely, and you've seen their growth. They are very difficult.
"They've got good talent ID. They’ve had players who moved on and done really well, very consistent, same manager, which always helps. And they've built real belief in their club. So I think they've earned the right to be in a semi-final, it’s not like they've had an easy sort of ride through it.
"They are a very, very difficult opponent away from home, absolutely. You just have to look at their record. But the balance of that is that Frankfurt had a pretty good home record as well, just as compelling. So I think you're in the semi-final, I don't think anyone would underestimate any opponent, but I certainly won't. I know them really well, and I know the challenge we're going to have to try and overcome them."