The Germany attacker is currently battling for form, though Postecoglou insists he is counting on the attacker this season.
He said, "It was 14 days ago those questions were asked of Brennan (Johnson). It's where we're at in this world. We just think, 'he's missed two chances, so he's hopeless'. No, he's not hopeless. All footballers at this level are very, very good footballers.
"Actually, last night Timo, in his first action, took on the winger and put in a brilliant cross for Will (Lankshear) and Will didn't quite get on the end of it.
“If that goes in, he's had a great assist. He then gets a one-on-one, if he scores that, if in the last two games he gets a couple of goals, then we'd be having a different conversation. But that's the fine lines.
"In terms of his general play, I think his last two games have been really good for us. He's been taking on his players, getting in the right areas.
"Yes, goals help. We've seen that with Brennan. But that doesn't mean he's not a good player and that's where I get really annoyed when they put everything on that moment to say he's not a good player. Of course he's a good player. He's a fantastic player.
"Scoring goals would help him, would help us, yes. But we'll persevere with him because I still think he's contributing to the team.
"Fourteen days ago I was sitting her answering questions about Dom Solanke and Brennan. Now we're talking about him in the England team and Brennan's scoring, so it's that fine balance. I think (Werner's) performances in the last two games have been better for us in terms of doing his role as a winger in our team.
"Yes, a goal would be great for him but not to say I expect more from him in that position."