Postecoglou confirmed he'll make up to three changes to his starting line-up for Saturday night's Brisbane showdown with the Asian heavyweight, which will decide top spot of Group A in the cup.
Australia will keep top billing with a win or a draw, but a loss will result in Korea Republic finishing first. Both nations have already secured quarter-final spots.
Jedinak has been battling an ankle injury suffered in the tournament-opening win against Kuwait last Friday.
The Crystal Palace captain missed the 4-0 win over Oman on Tuesday.
Postecoglou said Jedinak would train later on Friday, but wouldn't be rested for another game purely because the Socceroos have sealed a finals berth.
"The team selection for tomorrow will be the same as what we have done for the first two games, and that is we will pick a team we think can win," Postecoglou said.
"Everything else becomes secondary. The team we put out tomorrow will be the team we think gives us the best chance of success.
"If that includes Mile, great. If not, he will definitely be right for the quarter-final.
"From my perspective, it's all about making sure we don't bring him back when he hasn't fully recovered because that wouldn't be a smart move by us knowing that we have another game in four days time."
Australia will play a quarter-final on Thursday in either Melbourne or Brisbane.
Postecoglou said he would make about the same number of alterations to his starting side than he did for game two, when he made three.
"Rotations are not designed just to give everyone a go," he said.
"Each opponent gives us unique challenges and what we want to do is make sure that we play a high-energy sort of game.
"If we go through a tournament with just a core group of players, it just wouldn't work."
