Conclusion of the second round in Melbourne also sees home favourite Ashleigh Barty look to reach the last 32 against Camila Giorgi.
Djokovic, Federer, Halep and Kerber in action: Australian Open games to watch for Day 4
Ahead of the fourth day of action at the Australian Open on Thursday, the first grand slam of the 2018 tennis season, here are some of the main matches to watch out for. All times mentioned are UAE (+4 GMT).
The full schedule for Thursday's play on the main show courts can be found here.
Novak Djokovic (SRB X 14) v Gael Monfils (FRA)
Third match on Rod Laver Arena, likely to be around 7-8am start
This will be an interesting test for six-time Melbourne champion Djokovic. He looked good in winning his first match in beating Donald Young for the loss of only seven games.
Monfils, who has been as high as No 6 in the world, has fallen to No 39 due to an injury-hit 2017 season. The Frenchman is a tenacious player who can be a frustrating opponent with his ability to have long matches due to his excellent court coverage.
Djokovic is 14-0 against Monfils, so this does not scream upset. But Monfils will make the Serbian work and it will be a good test of his fitness and stamina after his six months away from the court.
- Australian Open order of play on Day 4: Federer, Djokovic, Kerber and Halep all up
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Ashleigh Barty (AUS X 18) v Camila Giorgi (ITA)
First match in evening session on Rod Laver Arena, noon
Barty is the highest seeded Australian in the women's draw and is her nation's big hope.
She should reach the third round for the second successive year against world No 100 Giorgi, though the Italian should be completely discounted, having beaten US Open champion Sloane Stephens earlier this month for the loss of only three games.
Jan-Lennard Struff (GER) v Roger Federer (SUI X 2)
Second match in evening session on Rod Laver Arena, should start around 1.30-2pm
Federer keeps trying to downplay his chances of winning his 20th major in Melbourne, but no-one is buying it.
The Swiss player looks to be in great form and he should be far too good for his German opponent and routine progress to the last 32 should be in order.
Angelique Kerber (GER x 21) v Donna Vekic (CRO)
Second match on Margaret Court Arena, should start around 6-6.30am
The 2016 champion Kerber is looking to be playing back near her best after an awful 2017.
The German has the form to go deep in the tournament, and while world No 47 Vekic could be a threat, she is unlikely to have the power to trouble her more experienced opponent.
Simona Halep (1 ROU) v Eugenie Bouchard (CAN)
First evening match on Margaret Court Arena, noon
Halep continues her push for a first major title and she should have no problems against Bouchard.
The Canadian has been competitive in Melbourne in the past, reaching the last four in 2014 and the quarter-finals in 2015.
But now down at No 83 she has rarely shown glimpses of that form and this should be a comfortable win for Halep.