Postecoglou's side travel to Hampden on Sunday with the chance of a fifth treble in six seasons very much on.
A hat-trick of derby wins would leave Postecoglou within touching distance of following in the footsteps of Jock Stein, Martin O'Neill, Brendan Rodgers and Neil Lennon in securing a clean sweep of domestic trophies.
Postecoglou said: "It's a cup semi-final so there's meaning on the end of it, there's consequences on the end of it.
"Every cup game you play, if you want to progress, you have got to perform on the day and get the job done on the day. There's no second chances.
"Particularly in a semi-final, it's going to be a tight game, it's going to be an unbelievable atmosphere.
"The players know the occasion, I don't have to disguise or dress it up in any other way than it's going to be a massive game with massive consequences, and it's exactly where we want to be."
A small band of 700 Celtic fans watched their side win 2-1 at Ibrox earlier this month after a two-year absence of away supporters in the derby fixture.
The neutral venue of Hampden will allow about 25,000 supporters from each side of the Glasgow divide to make an altogether different atmosphere.
"It will be a different experience and a unique one, and again something to embrace," Postecoglou said.
"It's what we all want to be involved in, games where at the end of it, hopefully you make memories that will last beyond your own lifetime.
"That's the opportunity that exists and it's one we are looking forward to."