Thiem broke the grand slam stranglehold of Roger Federer, Rafa Nadal and Novak Djokovic by winning the 2020 US Open.
However, a wrist injury the following year sidelined him for months, before a series of other fitness issues resulted in a slide to No.352 in the rankings.
The 30-year-old Austrian, now ranked 98th, won his first match at a grand slam since 2021 in New York in August before crashing out in the second round.
Thiem, who made the Melbourne Park final in 2020, can still gain direct entry into the main draw of the tournament if one player pulls out.
Emma Raducanu will gear up for the Australian Open in January by playing at the Auckland Classic. (James Ross/AAP PHOTOS)
Raducanu missed out on an Australian Open wildcard and will now have to take a similar path as her 2021 Flushing Meadows run when she became the first player in the open era to win a major after beginning in the qualifying rounds.
The 21-year-old Briton, now ranked No.299, will gear up for the first grand slam of the year by playing at the Auckland Classic, having fought her way back to fitness following operations on both wrists and an ankle in May.
Raducanu is five spots outside the main-draw cut-off.
The qualifying tournament starts on January 8, with the main draw from January 14-28.
