The tournament starts on 14 January but 32-year-old Gasquet will miss the competition as he recovers from a groin injury that forced him to miss France's Davis Cup final against Croatia in November.
"I've got a kind of strain at the top of my left leg," said Gasquet. "I hope to be back playing in February but what is certain that January is completely out for me."
Gasquet, who played his first Australian Open in 2003, reached the last 32 during the 2018 tournament where he lost to the eventual winner Roger Federer.
Final set tiebreak
Novak Djokovic, a six time winner of the event, is expected to top the men's seeding for the 2019 edition which will be the first to feature a tiebreak at 6-6 in the final set.
Rather than the standard seven point shoot-out, the winner will be the first player to reach 10 points by at least a two point margin.
“We asked the players – both past and present - commentators, agents and TV analysts and went from there,” said tournament direct Craig Tiley.
“We went with a 10-point tiebreak to ensure the fans still get a special finale to these often epic contests, with the longer tiebreak still then allowing for that one final twist or change of momentum in the contest.
"This longer tiebreak also can lessen some of the serving dominance that can prevail in the shorter tiebreak.
“We believe this is the best possible outcome for both the players and the fans around the world,” Tiley added.