The 35-year-old Serb had equaled with this victory the number of successes in Grand Slam tournaments with a 22nd title and regained the lead in the world rankings.
"He had a three centimeter tear in his hamstring," Craig Tiley, president of the Australian Tennis Federation, said in an interview with Australian radio SEN on Wednesday.
Djokovic had complained several times during the tournament of pain in his left thigh but did not give up the competition.
He beat the Greek Stefanos Tsitsipas 6-3, 7-6 (7/4), 7-6 (7/5) in the final.
He then announced that he would take a few days off and planned to return to the Dubai tournament, which will take place from February 27 to March 4.
© 2023 AFP