Novak Djokovic, the top seed at the Australian Open, will start his title defense against a qualifier or lucky loser and might face Andy Murray in the third round.
Djokovic, a 24-time major winner, is dealing with a wrist injury that affected him at the United Cup.
Greek seventh seed Stefanos Tsitsipas will face a tough challenge against former top 10 player Matteo Berrettini in the first round, with the potential of meeting Djokovic in the quarter-finals.
Spanish world number two Carlos Alcaraz, who defeated Djokovic at Wimbledon last year, will begin against French veteran Richard Gasquet.