As the new Celtic manager begins to closely assess the squad he has inherited, he is optimistic some of those who underperformed last season will respond positively to his methods.
But Postecoglou accepts there will be others who fall by the wayside in the coming weeks as he attempts to revitalise Celtic in the aftermath of their first trophy-free campaign in 11 years.
The 55-year-old will begin his first full week of pre-season training at Lennoxtown on Monday, laying the ground rules for a tenure which will begin in earnest with the first leg of the Champions League second qualifying round tie against Midtjylland of Denmark at Celtic Park on July 20.
“My experience tells me that in the environment I create, some people thrive for sure,” said Postecoglou.
“But others will really struggle - and you don’t have a choice in who they are going to be. That’s how I measure staff and players.
“I know people are keen to know what changes we are going to make. But I come from the perspective that we would rather make the decisions ourselves, after we change the environment, rather than relying on (others).
“There are decisions I have to take responsibility for, so I will make them. I think some of the players will definitely thrive in the environment. That will make decisions easy.”