The Huddersfield Town ace was missing through illness as Australia crashed to a 2-0 defeat to Japan last week to leave their Russia 2018 finals hopes hanging by a thread.
The loss in Saitama left the Socceroos outside the two direct qualification places in Asia Group B but level on 16 points with Saudi Arabia behind the already qualified Japan heading into the final pool game.
The Socceroos are two goals inferior to the Saudis on goal difference and need to hammer the Thais in Melbourne in case the Green Falcons beat Japan in Jeddah later Tuesday.
Depending on results, either Australia or Saudi Arabia will be consigned to facing South Korea, Uzbekistan, Syria or China from Group A in an Asian eliminator before meeting the CONCACAF play-off winner in the final showdown for a place in Russia.
Under-pressure Socceroos coach Ange Postecoglou believes his side has the arsenal to beat the Thais comfortably and automatically qualify.
“We have just got to play well,” he told reporters.
“If you don’t play well you leave things to chance, and we don’t want to leave things to chance.
“We’ve got to make sure we stay focused and play our football, keeping it at a high tempo and pressuring the opposition from start to finish. When we do that things tend to fall into place.”
Mooy is the key midfield creator and crucial to Australia’s attack which was criticised as slow and unimaginative against Japan despite a welter of possession.
Postecoglou said Mooy was ready to return along with tall striker Tomi Juric, who started off the bench against the Japanese.
“They are fine, they had a run on the weekend. Aaron was due to start the last game, but obviously on the day of the game he didn’t pull up,” Postecoglou said.
“Tomi could have started as well, but he hadn’t trained at all and we just felt that it was going to be too much of a risk for him to start.”
Thailand are bottom of the group but the Socceroos needed two Mile Jedinak penalties to force a 2-2 draw in Bangkok last November.
The Thais have only picked up two points in their nine games in this qualifying competition so far.