<p class="title">Roger Federer and Novak Djokovic are both gunning for a record seventh Australian Open crown from Monday, but Andy Murray will make his last appearance in Melbourne as the era of the "Big Four" draws to a close.</p>.<p class="bodytext">Number one Djokovic and third seed Federer face a stern challenge from the likes of youthful force Alexander Zverev, seeded four, who is still looking for a first major to cement his place as torch-bearer for the next generation.</p>.<p class="bodytext">But Murray dropped a pre-Grand Slam bombshell, breaking down during a tear-filled press conference as he revealed chronic hip pain means he will retire after Wimbledon -- if he can carry on that long.</p>.<p class="bodytext">And question marks remain over the fitness of world number two Rafael Nadal who pulled out of his Brisbane warm-up but arrived in Melbourne professing he was "fully fit" and promising to unleash a remodelled serve.</p>.<p class="bodytext">It all means the era of the "Big Four" is almost over after a season in which Federer -- who opens his title defence against Denis Istomin on Monday -- rolled back the years on Rod Laver Arena to lift an emotional 20th Grand Slam.</p>.<p class="bodytext">It put him on a par with other six-time Australian Open winners Djokovic and Roy Emerson -- although the Australian great's victories all came before the Open era.</p>.<p class="bodytext">By contrast, the 31-year-old Djokovic endured a miserable early Melbourne exit in 2018, followed by elbow surgery and a string of disappointing results that saw him drop outside the top 20.</p>.<p class="bodytext">But since winning a fourth Wimbledon in July, the Serb rose inexorably back to number one by losing only three further matches -- one of which was to Zverev at the ATP Finals.</p>.<p class="bodytext">Djokovic won his third US Open in September to put him on 14 Grand Slams -- three behind Nadal and six behind Federer.</p>.<p class="bodytext">And Djokovic said on Sunday he was delighted to be back in Melbourne where his rise to greatness all began in 2008 with his first Grand Slam win.</p>.<p class="bodytext">"It was my first major trophy, that obviously served as a great springboard for my career," Djokovic said as he prepared to open his assault on a seventh crown against American Mitchell Krueger on Tuesday.</p>.<p class="bodytext">"It opened a lot of doors for me. It allowed me to believe in myself that I can actually win the biggest tournaments in the world, challenge the best players in the world."</p>.<p class="bodytext">Federer, now 37, remains the chief threat to the Serb and he sounded a warning Sunday.</p>.<p class="bodytext">"I'm playing good tennis. I'm confident that I think it needs a good performance by my opponent probably to beat me," said the Swiss master, who warmed for Melbourne with victory in Perth's Hopman Cup.</p>.<p class="bodytext">Second-ranked Nadal, 32, pulled out of Brisbane with a thigh strain although he returned for an exhibition in Sydney and insisted at the weekend his fitness woes were behind him.</p>.<p class="bodytext">"I feel good. If I am not feeling good, I will not be here," he said before revealing he had remodelled his serve.</p>.<p class="bodytext">"There are always things to improve," said the Spaniard, who faces Australian wildcard James Duckworth on Monday.</p>.<p class="bodytext">Djokovic picked young guns Zverev of Germany, Borna Coric of Croatia, Karen Khachanov of Russia and Greece's Stefano Tsitsipas as key threats to the top three.</p>.<p class="bodytext">"It's just a matter of time when we will see some of them competing in the last stages of Grand Slams," said Djokovic.</p>.<p class="bodytext">Zverev, 21, starts the Australian Open full of confidence after an impressive warm-up to reach the final of Perth's mixed teams Hopman Cup, despite his terrible record at Grand Slams.</p>.<p class="bodytext">He has never got beyond the third round in Melbourne and faces Slovenia's Aljaz Bedene in his opener on Tuesday.</p>.<p class="bodytext">Last year, seeded four, he crashed out in the last 32 to South Korea's Chung Hyeon and has only reached one quarterfinal in 14 major appearances.</p>.<p class="bodytext">Home fans will look to new Sydney champion and 27th seed Alex de Minaur, who faces Portugal's Pedro Sousa on Monday, and the temperamental Nick Kyrgios.</p>.<p class="bodytext">Kyrgios has a tough opening match against former world number three Milos Raonic and then a possible clash with former Australian Open champion Stan Wawrinka in round two.</p>
<p class="title">Roger Federer and Novak Djokovic are both gunning for a record seventh Australian Open crown from Monday, but Andy Murray will make his last appearance in Melbourne as the era of the "Big Four" draws to a close.</p>.<p class="bodytext">Number one Djokovic and third seed Federer face a stern challenge from the likes of youthful force Alexander Zverev, seeded four, who is still looking for a first major to cement his place as torch-bearer for the next generation.</p>.<p class="bodytext">But Murray dropped a pre-Grand Slam bombshell, breaking down during a tear-filled press conference as he revealed chronic hip pain means he will retire after Wimbledon -- if he can carry on that long.</p>.<p class="bodytext">And question marks remain over the fitness of world number two Rafael Nadal who pulled out of his Brisbane warm-up but arrived in Melbourne professing he was "fully fit" and promising to unleash a remodelled serve.</p>.<p class="bodytext">It all means the era of the "Big Four" is almost over after a season in which Federer -- who opens his title defence against Denis Istomin on Monday -- rolled back the years on Rod Laver Arena to lift an emotional 20th Grand Slam.</p>.<p class="bodytext">It put him on a par with other six-time Australian Open winners Djokovic and Roy Emerson -- although the Australian great's victories all came before the Open era.</p>.<p class="bodytext">By contrast, the 31-year-old Djokovic endured a miserable early Melbourne exit in 2018, followed by elbow surgery and a string of disappointing results that saw him drop outside the top 20.</p>.<p class="bodytext">But since winning a fourth Wimbledon in July, the Serb rose inexorably back to number one by losing only three further matches -- one of which was to Zverev at the ATP Finals.</p>.<p class="bodytext">Djokovic won his third US Open in September to put him on 14 Grand Slams -- three behind Nadal and six behind Federer.</p>.<p class="bodytext">And Djokovic said on Sunday he was delighted to be back in Melbourne where his rise to greatness all began in 2008 with his first Grand Slam win.</p>.<p class="bodytext">"It was my first major trophy, that obviously served as a great springboard for my career," Djokovic said as he prepared to open his assault on a seventh crown against American Mitchell Krueger on Tuesday.</p>.<p class="bodytext">"It opened a lot of doors for me. It allowed me to believe in myself that I can actually win the biggest tournaments in the world, challenge the best players in the world."</p>.<p class="bodytext">Federer, now 37, remains the chief threat to the Serb and he sounded a warning Sunday.</p>.<p class="bodytext">"I'm playing good tennis. I'm confident that I think it needs a good performance by my opponent probably to beat me," said the Swiss master, who warmed for Melbourne with victory in Perth's Hopman Cup.</p>.<p class="bodytext">Second-ranked Nadal, 32, pulled out of Brisbane with a thigh strain although he returned for an exhibition in Sydney and insisted at the weekend his fitness woes were behind him.</p>.<p class="bodytext">"I feel good. If I am not feeling good, I will not be here," he said before revealing he had remodelled his serve.</p>.<p class="bodytext">"There are always things to improve," said the Spaniard, who faces Australian wildcard James Duckworth on Monday.</p>.<p class="bodytext">Djokovic picked young guns Zverev of Germany, Borna Coric of Croatia, Karen Khachanov of Russia and Greece's Stefano Tsitsipas as key threats to the top three.</p>.<p class="bodytext">"It's just a matter of time when we will see some of them competing in the last stages of Grand Slams," said Djokovic.</p>.<p class="bodytext">Zverev, 21, starts the Australian Open full of confidence after an impressive warm-up to reach the final of Perth's mixed teams Hopman Cup, despite his terrible record at Grand Slams.</p>.<p class="bodytext">He has never got beyond the third round in Melbourne and faces Slovenia's Aljaz Bedene in his opener on Tuesday.</p>.<p class="bodytext">Last year, seeded four, he crashed out in the last 32 to South Korea's Chung Hyeon and has only reached one quarterfinal in 14 major appearances.</p>.<p class="bodytext">Home fans will look to new Sydney champion and 27th seed Alex de Minaur, who faces Portugal's Pedro Sousa on Monday, and the temperamental Nick Kyrgios.</p>.<p class="bodytext">Kyrgios has a tough opening match against former world number three Milos Raonic and then a possible clash with former Australian Open champion Stan Wawrinka in round two.</p>