"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 (English) 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, is in good, solid form.
"It makes sense to bring him in and have a look at him in a national team environment.''
Wright's selection comes as Postecoglou revamps a defence without overlooked veteran centre-backs Lucas Neill and Sasa Ognenovski and injured stopper Trent Sainsbury, ruled out by a knee injury.
Postecoglou's squad has an average age of 22.5-years-old and features 10 players from the domestic A-League.
Only two squad members - Wright and Ben Halloran - have yet to make a senior international appearance but most others have played only a handful of games for the Socceroos.
"Inexperience, but at the same time a great opportunity for some of these younger players to forge their own national team careers,'' Postecoglou said.
"We needed to change the direction of our national team. This wasn't going to be an adjustment; this was a meaningful change and we needed to regenerate the team.
"There was no doubt in my mind that we needed to make some meaningful change in the players we selected and, at the same time, understand that it's a World Cup.
"I have said all along if people had the form and fitness, that regardless of age or experience, if that form or fitness was warranted, they would be in the squad. And I think we have managed to do that.''
Postecoglou named midfielder Mile Jedinak, who is vying with Tim Cahill to replace Neill as captain, despite the Crystal Palace skipper being sidelined for the next three weeks with a groin strain.
Four goalkeepers were named in the squad with Belgium-based Mat Ryan the likely first-choice ahead of Borussia Dortmund's Mitch Langerak and A-Leaguers Eugene Galekovic and Mark Birighitti.
Postecoglou will cut three players from the squad the day after Australia's friendly against South Africa in Sydney on May 26.
The final 23-man squad will be named in Brazil on June 2 ahead of World Cup fixtures against Chile on June 13, the Netherlands on June 18 and Spain on June 23.
Socceroos squad:-
Goalkeepers: Mark Birighitti (Newcastle Jets), Eugene Galekovic (Adelaide United), Mitchell Langerak (Borussia Dortmund, Germany), Mat Ryan (Club Brugge, Belgium)
Defenders: Jason Davidson (Heracles Almelo, Netherlands), Ivan Franjic (Brisbane Roar), Curtis Good (Dundee United, Scotland), Ryan McGowan (Shandong Luneng, China), Matthew Spiranovic (Western Sydney Wanderers), Alex Wilkinson (Jeonbuk Hyundai, South Korea), Luke Wilkshire (Dinamo Moscow, Russia), Bailey Wright (Preston North End, England)
Midfielders: Oliver Bozanic (Luzern, Switzerland), Mark Bresciano (Al Gharafa, Qatar), Joshua Brillante (Newcastle Jets), James Holland (Austria Vienna, Austria), Mile Jedinak (Crystal Palace, England), Massimo Luongo (Swindon Town, England), Matthew McKay (Brisbane Roar), Mark Milligan (Melbourne Victory), Tommy Oar (FC Utrecht, Netherlands), Tommy Rogic (Melbourne Victory) Adam Sarota (FC Utrecht, Netherlands), James Troisi (Melbourne Victory), Dario Vidosic (FC Sion, Switzerland)
Forwards: Tim Cahill (New York Red Bulls, USA), Ben Halloran (Fortuna Dusseldorf, Germany), Josh Kennedy (Nagoya Grampus, Japan), Matthew Leckie (FSV Frankfurt, Germany), Adam Taggart (Newcastle Jets).
-AAP
