He stressed the need for his team to be at their best, both physically and mentally.
Regarding squad fitness, Postecoglou confirmed that Micky van de Ven will not be available as the club carefully manages his recovery.
He told reporters: “In terms of availability from last week, everyone is fine and got through okay. So no issues there. Kevin (Danso) and Mathys (Tel) are both available. They have trained and are cleared to play so they are all good.
“The rest of them, no one is available tomorrow. With Micky, and Romero to a certain extent, I kind of feel we have to be a bit more conservative with them. Micky got through the game alright but I don’t think he feels ready for that step up to the Premier League, the intensity of it. Same with Romero.
After losing Radu for the rest of the season, which is really disappointing for him and for us, my view is and I made the decision that I don’t want to risk losing these guys. We are going to keep them ticking over in training and try to make sure they are absolutely ready without any more setbacks. The other guys are inching closer as well but similar sort of mindset with them.”
On Danso, he added: “He will play. Whether he starts or not we will take a look because we have another game three days later and that has been our existence for quite a while now. You are right, Ben (Davies), Archie, Pedro (Porro) has played every minute of football we have had for the last three months, but the boys are handling it okay and the performances are still stacking up.
“It’s great to get Kevin in. He is ready to play. Whether he starts or he comes on we will make a decision. It’s really important he is part of it now because losing Radu was a massive blow so having him available is good.”