The Premier League side enjoyed a win over Manchester City in the Carabao Cup in midweek.
However, they lost Micky Van de Ven to injury, while Son Heung-min is still a doubt as well.
"Main one, is Micky, he has sort of strained his hamstring," Postecoglou said to reporters
"It's not too serious, but probably after the international break for him."
He then added: "He was disappointed obviously. He was really looking forward to the game so he was a bit emotional. It is definitely not, knock-on-wood, a bad one like last time which kept him out for quite a while.
"He will work hard and the good thing is there is an international break in there which is an extra two weeks for us. So hopefully it means he doesn’t miss too much football.”
"The other ones who were a bit sore were Romero and Werner but at the moment there is still a chance for the weekend," Postecoglou continued.
"Sonny has trained today so if he gets through training tomorrow, he should be okay."