Despite not playing a fixture since November, Australia have moved to 44th in the rankings, up from 47th in December.
The Socceroos are now the third highest-ranked team in Asia, behind Iran (29th) and Korea Republic (36th).
Argentina remain the world’s top ranked side, followed by Germany, Brazil and Chile.
Postecoglou's side are back in action in March with a crucial away fixture against Iraq (119th) on March 23 before returning home to tackle UAE (64th) in Sydney just five days later.
Australia currently sit third in Group B following three straight draws in their bid to qualify for Russia 2018, one point behind Saudi Arabia (48th) and Japan (46th)
The Socceroos have been drawn to play Chile and Germany at the 2017 Confederations Cup in Russia along with the winner of next month’s Africa Cup of Nations.