* Average age of 25 in Socceroos squad
* Two uncapped players included
* Jedinak out for up to three weeks
By Nick Mulvenney
SYDNEY, May 14 (Reuters) - Australia coach Ange Postecoglou was true to his word and picked a youthful 30-man Socceroos preliminary squad for the World Cup finals in Brazil on Wednesday.
Postecoglou took over from German Holger Osieck just six months ago and had promised to ease out Australia's ageing 'golden generation' in favour of younger players.
He has selected a provisional party with an average age of 25 for the June 12-July 13 tournament, where Australia have been drawn with world champions Spain, the Netherlands and Chile.
The squad is littered with players in their early 20s with two uncapped contenders for a ticket to South America in forward Ben Halloran and his fellow 21-year-old Bailey Wright, a central defender.
Halloran has been in prolific form for Fortuna Duesseldorf in the German second tier, while Wright will be hoping to help Preston North End to promotion to England's second flight before joining the squad.
Other mild surprises were the inclusion of A-League goalkeepers Eugene Galekovic and Mark Birighitti ahead of Liverpool reserve Brad Jones.
Midfielder James Troisi, who has been on loan at Melbourne Victory from Atalanta, Swindon midfielder Massimo Luongo and Adam Taggart, who scored 16 goals for the Newcastle Jets last season, have also been rewarded for their form.
"The majority of them have had strong seasons this year and I guess for a lot of them, hopefully, they have a similar fire in their belly to myself in wanting to prove themselves," Postecoglou told a news conference in Sydney.
"I had some specific criteria - form, fitness and an eye for the future - and I think this squad reflects that."
Bayer Leverkusen forward Robbie Kruse (knee), Middlesbrough's Rhys Williams (Achilles) and his fellow defender Trent Sainsbury (knee) were all ruled out by injury.
Experienced campaigners such as goalkeeper Mark Schwarzer, former captain Lucas Neill, midfielder Brett Holman and forward Harry Kewell have either jumped or been pushed into international retirement since Postecoglou took over.
"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," Postecoglou added.
"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."
The players will gather in Gosford, just north of Sydney, for a training camp this week and three players will be cut after a friendly against South Africa on May 26.
There was reassurance about the fitness of Mile Jedinak, who is the leading candidate to captain the side but suffered a groin injury in his final match of the season for Crystal Palace last weekend.
"He won't be out for more than two or three weeks," said Postecoglou, who will name his final 23-man squad on June 2.
"We were going to give him time off anyway and he'll be in Gosford on Sunday."
Goalkeepers - Mathew Ryan (Club Bruges), Mitchell Langerak (Borussia Dortmund), Eugene Galekovic (Adelaide United), Mark Birighitti (Newcastle Jets)
Defenders - Curtis Good (Dundee United), Jason Davidson (Heracles Almelo), Matthew Spiranovic (Western Sydney Wanderers), Luke Wilkshire (Dynamo Moscow), Ivan Franjic (Brisbane Roar), Bailey Wright (Preston North End), Ryan McGowan (Shandong Luneng), Alex Wilkinson (Jeonbuk Hyundai Motors)
Midfielders - Joshua Brillante (Newcastle Jets), Oliver Bozanic (Luzern), Mark Bresciano (Al Gharafa, Qatar), James Holland (Austria Vienna), Mile Jedinak (Crystal Palace), Mark Milligan (Melbourne Victory), Dario Vidosic (Sion), Adam Sarota (Utrecht), Matt McKay (Brisbane Roar), James Troisi (Atalanta), Massimo Luongo (Swindon)
Forwards - Tim Cahill (New York Red Bulls), Josh Kennedy (Nagoya Grampus), Matthew Leckie (FSV Frankfurt 1899), Tommy Oar (Utrecht), Tomas Rogic (Celtic), Ben Halloran (Fortuna Duesseldorf), Adam Taggart (Newcastle Jets). (Editing by Greg Stutchbury/Peter Rutherford)