But Postecoglou will wait until the players come into camp to decide whether or not Rogic has done enough to sew up the attacking midfield role.

He  says at this stage he could pick out "two or three" starting XI's in a number of formations and still feel confident the Socceroos could overcome looming tests against Saudi Arabia and Japan.

"Hopefully that makes us difficult to match up against," Postecoglou said.

"Tommy's certainly a part of that but he's not guaranteed to start, as is anyone else in the group. What I do know is when they come in any role they do play, they do it to the best of their ability."

Rogic watched on from the bench as Celtic were humbled by Spanish powerhouse Barcelona 7-0 in the group stage of the UEFA Champions League despite his recent run of good form.

While Postecoglou said Rogic "would have much rather played than been on the bench" he harbours no worries about the 23-year-old's ability to play a role in big games.

"I think he's got a really good temperament," Postecoglou said.

"Every time he's played this year he's made an impact - whether that's with a goal, a he's got quite a few from infield, or assist, or just being really influential in the game."

Postecoglou said the upcoming fixtures kick off a "real challenging" period for the Socceroos with a home game against Japan sandwiched by two away matches.

The Socceroos mentor said as soon as the qualifying draw was released he knew his side was in for "a tough start".

"We know in the back half of next year we'll have the likes of Thailand, Saudi, UAE all coming to Australia, [and] we'll also have Iraq but in a neutral venue," Postecoglou said.

"We knew this first five-game series in the back half of this year was the one that was really going to challenge us.

"We've had a good strong start with the two wins and two strong performances, which is pleasing, but under no illusions that these two games will be just as tough, but for different reasons."

Postecoglou said if the Socceroos can manage to get through the remainder of 2016's fixtures "fairly unscathed" his side will be well on track for World Cup qualification.

"I think the challenges will still be there and real important for us to continue our strong performances," he said.

"I think if we can perform like we did in our first two games it means we're going to be hard to beat. Having the points on the board already means pressure is on the opposition to a certain extent."

The Socceroos travel to face Saudi Arabia in their next World Cup qualifier on October 7 before backing up four days later against Japan in Melbourne.