Spurs are on track to finish in the bottom half of the Premier League table, though face Bodo/Glimt in the second-leg of their Europa League semifinal holding a 3-1 lead.
Postecoglou, ahead of Sunday's trip to West Ham, said: "I think we’ve understood that that’s the space we’re in now, for a little while. If you look at the players’ performances, if it was affecting them you would have seen that in the big games. I think they have performed really well in Europe.
“Our league form has obviously been nowhere near where it should be, and there’s a narrative around that, but I think the players have been really good at making sure this opportunity (isn't wasted).
“We could have been having a great season and be third or fourth in the table and the opportunity is still the same. Whether you’re third or 16th, it’s still the semi-final of the Europa League.”
We must take this chance
The Spurs manager continued: “This club has experienced so much in the last 15 years and longer in Europe that they know they don’t come around often, so you want to take it. What’s happening in your season almost becomes irrelevant once the opportunity presents itself. It’s an opportunity this group of players have earnt.
“I’d hate to think people don’t think I’ve been preparing the same I always have for these games and want to win these games. We were hugely disappointed with Liverpool, notwithstanding the fact they were outstanding all year and it was always going to be a difficult day whichever way we went.
“I was really hard on the players the day after the game. I wasn’t really sure how they would react to it, but I just felt we need to feel that pain. We’ve got an opportunity to do something special and I don’t want to let that slip because of us losing focus on what is important.”