The biggest so far has been the inclusion of the largely unknown and certainly unheralded, Bailey Wright, in Australia’s provisional 30-man squad announced on Wednesday.
The 21-year-old Melbourne-born Preston North End defender impressed Postecoglou during his European scouting mission in February.
Now the centre-back from the English third tier has the chance to press his case for a place in the revamped Socceroos backline.
"He's been on our radar for a little while," Postecoglou said of the former youth international.
"But he has had some really strong consistent form at Preston North End in a team that has done well and is on the verge of promotion to the Championship.
"Particularly playing in his position, we have had some injury clouds over a couple of our centre-backs, so he's one that played almost 50 games this year and is in good, solid form.
"It makes sense to bring him in and have a look at him in a national team environment."
Postecoglou has backed youth over experience in the 30-man provisional squad for his World Cup training camp ahead of their flight to Brazil in two weeks' time.
"Yes there's inexperience but at the same time it's a great opportunity for some of these younger players to forge their own national team careers," Postecoglou added.
"I've been really impressed with a lot of the young guys, particularly (Josh) Brillante and (Adam) Taggart in the A-League. Ben Halloran has really come on this season in Germany and these guys are 20, 21-years-old.
"On reflection the way Curtis Good handled that step up in the Ecuador game gave me even more confidence thatthe young players, given the opportunity will take it.
"It's exciting to see them but they've obviously still got to perform in this whole group of 30 to get on the plane...how they perform in the context of this camp will be an indicator as well."
The Aussies face the footballing might of Spain, the Netherlands and Chile in Group B but far from being fearful Postecoglou is hoping fans of the green and gold are excited by what they witness from his youthful line-up.
"There are over 15,000 Aussies going over to watch the games, the whole nation will watch in the middle of the night and I want them to get up and be excited about watching this team," he said.
"Then our responsibility is to excite them when they watch, give them a glimpse into the future and maybe take them on a bit of a wild ride where the unexpected happens."