The changes from the Socceroos squad for the upcoming international with England on 28 May (AEST) include Cahill (Hangzhou Greentown FC), Mark Birighitti (Newcastle Jets), Nathan Burns (FC Tokyo), Jason Geria (Melbourne Victory), Alex Gersbach (Rosenborg), Apostolos Giannou (Guangzhou R&F), Mathew Leckie (FC Ingolstadt), Ryan McGowan (Henan Jianye), Trent Sainsbury (Jiangsu Suning), Matthew Spiranovic (Hangzhou Greentown).
"I'm not going to a World Cup again sweating on guys being fit and not having options if they're not," Postecoglou said.
"We've got to go into every camp, every game knowing that if we're missing one or two ... we've got others to call on."
Birighitti has also been drafted into for the squad for the England clash, replacing Mitch Langerak, who has had to withdraw due to injury.
With The Dodoni Series between Australia and Greece falling inside the FIFA window, Postecoglou was able to consider all available players when selecting the squad.
“The matches against Greece are about continuing to expose our players to a high level of international football,” Postecoglou said.
“The competition and intensity of these matches will definitely give us that and gives us the right preparation for the next round of World Cup qualifiers and the Confederations Cup.
“Playing in front of big home crowds is an opportunity both for the players and the fans to build on the great atmosphere that has been created during the first round of World Cup qualifiers in Perth, Canberra, Adelaide and Sydney.”
Postecoglou said a rare home international against European opposition was another benefit.
“The Asian Cup and the first round of World Cup qualifiers put our focus on Asian teams and conditions but it’s important to confront a range of styles,” Postecoglou said.
“Greece will present a different set of technical and tactical challenges and they have many players at the top level in Europe.
“Of course, the Greek Australian community will have special affinity to the matches and that will add to the occasion in Sydney and Melbourne.”
Milos Degenek, Brad Inman, Jamie Maclaren and Stefan Mauk could make their international bows in England, with Geria, Gersbach and Maclaren again possible home debutants.
Postecoglou stressed that any cap won would be deserved.
"The two Greece games, one being after the other, I'll take an opportunity to get a look at most of the guys. It's important in these friendly games we do that," he said.
"But we're putting out teams that we think will be able to play our football and give an opportunity to as many as possible."
Massimo Luongo won't travel to Australia as his wife is expecting their first child next month.
Socceroos squad for the internationals against Greece
| Name||Club, Country||A International Caps (Goals)|
|Mark BIRIGHITTI (gk)||Newcastle Jets||1 (0)|
|Nathan BURNS||FC Tokyo||20 (3)|
|Tim CAHILL||Hangzhou Greentown FC||89 (47)|
|Adam FEDERICI (gk)||A.F.C. Bournemouth||15 (0)|
|Jason GERIA||Melbourne Victory FC||-|
|Alex GERSBACH||Rosenborg BK||-|
|Apostolos GIANNOU||Guangzhou R&F FC||1 (0)|
|Chris IKONOMIDIS||U.S. Salernitana 1919||3 (0)|
|Jackson IRVINE||Ross County||2 (0)|
|Mile JEDINAK||Crystal Palace FC||62 (12)|
|Robbie KRUSE||Bayer 04 Leverkusen||40 (4)|
|Mathew LECKIE||FC Ingolstadt 04||29 (2)|
|Jamie MACLAREN||Brisbane Roar FC||-|
|Ryan MCGOWAN||Henan Jianye FC||15 (0)|
|Mark MILLIGAN||Baniyas F.C.||46 (5)|
|Aaron MOOY||Melbourne City FC||13 (5)|
|Josh RISDON||Perth Glory FC||2 (0)|
|Tom ROGIC||Celtic FC||15 (5)|
|Mathew RYAN (gk)||Valencia CF||23 (0)|
|Trent SAINSBURY||Jiangsu Suning FC||14 (1)|
|Brad SMITH||Liverpool FC||6 (0)|
|Matthew SPIRANOVIC||Hangzhou Greentown FC||30 (0)|
|Bailey WRIGHT||Preston North End FC||10 (1)|