Tennis: Australian Open - Day six preview

World No 1 Novak Djokovic is in action today at the Australian Open. Photo / Getty Images

Novak Djokovic looks for top gear, Kei Nishikori looks for more history, David Ferrer looks to surprise and Victoria Azarenka looks to be capable of anything as we preview day six of the 2015 Australian Open.

Don't miss: Novak Djokovic vs Fernando Verdasco
With all the dramas surrounding Roger Federer and Rafa Nadal, it almost feels like Djokovic has been ignored at this tournament, as much as that is possible for the top seed. But expect the Serbian to click into gear in this match, up against Verdasco who is enjoying a career renaissance. The left handed Spaniard has tasted victory against Djokovic on four occasions, but has never beaten a current world No 1.
Head to head: Djokovic 6-4

Don't bother: John Isner vs Gilles Muller
Unless you like the prospect of watching a million aces and almost no rallies - find something else to do while this match is on. Five of the eight sets these players have contested have ended in a tie-break. Isner is bidding for his best Australian Open result since 2010, when he reached the fourth round while Muller has already equalled his best performance in Melbourne.
Head to head: Isner leads 3-0

Expect a beauty: David Ferrer vs Gilles Simon
Two of the most underrated players in the sport should produce a brilliant match up. Ferrer is a superb counter-puncher while Simon is an excellent shot maker. Expect long rallies and plenty of drama. Simon won their last encounter at the US Open in four sets, breaking a run of three successive defeats to the Spanish player.
Head to Head: Ferrer leads 5-2

Spain's David Ferrer takes on Gilles Simon today. Photo / Getty Images

Worth a watch: Barbora Zahlavova Strycova vs Victoria Azarenka
Two of the best personalities off the court should produce a ripper on it. Zahlavova is in the form of her life and never gives up while Azarenka is probably the best world No 44 the Australian Open has ever seen. The Czech is looking to equal her best grand slam result (reached quarter-finals at 2014 Wimbledon) while Azarenka surely has her eye on a third final at Melbourne Park.
Head to Head: Azarenka leads 3-0

World No 44 Victoria Azarenka. Photo / Getty Images

Also worth a watch: Kei Nishikori vs Steve Johnson
The Japanese star will be looking to create more history at this grand slam, after his amazing effort in New York last year when he beat three top 10 players in consecutive matches to reach the final. Nishikori has reached the last eight here once before, as 24th seed in 2012. World No 38 Johnson is in career best form, having risen from outside the top 150 over the past year, though Nishikori boasts 11 consecutive wins over American opponents.
Head to head: Nishikori leads 2-0

Best of the rest:
• Venus Williams vs Camila Giorgi: Fascinating to see the continuing resurgence of the 2015 ASB Classic champion against the young Italian.
Head to head: First meeting

• Stan Wawrinka vs Jarkko Nieminen: The defending champion versus the pride of Finland.
Head to head: 1-1

• Milos Raonic vs Benjamin Becker: Canadian eighth seed vs German veteran
Head to head: Raonic leads 2-1

• Serena Williams vs Elina Svitolina Surely only one result as the American gets better with every match.
Head to head: Williams 1-0

Kiwis in action:
Michael Venus and Austrian Oliver Marach play their second round doubles match this afternoon.

Stat of the day:
If Venus Williams wins her match today she will progress to the fourth round of the grand slam for the first time since Wimbledon in 2011.