Serena Williams and Andy Murray will return to the Australian Open next month, the tournament confirmed on Wednesday as it announced that the world's top 102 women and top 101 men are set to compete.
Britain's Murray has been struggling to recover from a hip injury and skipped this year's contest, but has entered using his protected ranking.
Williams also missed the 2018 tournament after giving birth to her first child. The seven-time champion, who last won the Grand Slam while eight-weeks pregnant in 2017, has had a rocky return to the game this year.
World number ones Novak Djokovic and Simona Halep head up the men's and women's fields respectively while Roger Federer and Caroline Wozniacki will return to defend their titles.
Wednesday's announcement came after British media reported that the Australian Open plans to follow Wimbledon's lead and introduce a tie-break in the final set in a bid to reduce the length of matches.
However, rather than playing it at 12-12 and with the first-to-seven rule as Wimbledon plans to do next year, the Australians will play a tie-break at 6-6 and use a first-to-ten-points version, according to the Telegraph.
The British paper said Tennis Australia had applied to the Grand Slam Board for permission to use the scoring system and had received permission on a year-by-year trial basis.