Mark Bresciano, Tommy Oar, Chris Herd and Ivan Franjic all missed Friday's 0-0 draw with United Arab Emirates (UAE) through injury or illness, while star striker Tim Cahill was only well enough to play the last 15 minutes.
But after training strongly since the squad arrived in Doha, all five will get some vital minutes as the side look to increase their unbeaten streak to three matches.
"Timmy (Cahill), Bresc (Bresciano), Tommy (Oar), Chris Herd and Ivan (Franjic) are all good. It will be about getting them on the pitch tomorrow and giving them a chance to play," Postecoglou told FFA TV.
"So far they have recovered well and the guys that played the last game, apart from James Holland, all feel pretty good about it.
"We’ll make some changes because we want to have a look at some other players and give them an opportunity to play. If everything goes well in the last session it will probably be four or five."
Western Sydney Wanderers defender Nikolai Topor-Stanley is another likely to be given a run against Qatar, while Mitch Langerak or Adam Federici may be given a shot as goalkeeper.
Like Saturday's clash with UAE, it is expected to be another challenging test for Australia in more steamy conditions in Doha but Postecoglou wants to see more improvement from his troops.
"The beauty of these two games for us they're both (UAE and Qatar) are preparing for the Gulf Nations (Cup)," the coach said.
"It's a big tournament for them so they are well ahead in their preparations and taking these two games seriously, which is ideal for us.
"We've got some clear objectives in these games and that is to grow our playing pool and give some guys an opportunity and we'll continue to do that.
"Along the way hopefully our performances keep heading in the right direction but it still about making sure come the first game in the (AFC Asian Cup) we've got the best possible 23 selected, and they come into camp already having experienced the kind of football we're going to have to play in the tournament."
