Roger Federer has recently become the most successful player in Hopman Cup history.
Federer and Belinda Bencic won the mixed doubles for Switzerland in Perth last week, beating Germans Alexander Zverev and Angelique Kerber 2-1 in the final for the second year running.
“Let us have one!” Zverev begged Federer jokingly afterwards.
With the Australian Open starting in Melbourne on Monday, Federer - ranked as the world's number three - will be targeting a third successive triumph at the tournament.
The 37-year-old insists world number one Novak Djokovic is the favourite, but acknowledged that he is part of the "usual suspects" in contention to go all the way.
'The Big Four' - Federer, Djokovic, Rafa Nadal, and Andy Murray - are the "usual suspects". The four stars have dominated tennis for years, and have won 54 of the last 60 Grand Slam titles between them.
Djokovic, Nadal, and Federer make up the top three in the world rankings, with Murray's injury issues causing the Scotsman to drop to 240th.
All four are now in their thirties, and their stunning dominance will eventually come to an end.
The Big Four Three
Andy Murray left his press conference in tears today.
After leaving the room to compose himself, the 31-year-old revealed that his retirement is imminent due to his ongoing hip injury issues.
The Scottish star has had a nightmare two years of injury, and has been playing through the pain caused by his hip for 20 months.
"Obviously I've been struggling for a long time, and I've been in a lot of pain for about 20 months now," he said today ahead of his clash with Roberto Bautista Agut in the first round on Monday.
When asked if the Australian Open could be his last tournament, Murray confirmed that this could be a possibility, but revealed his wish to retire after Wimbledon.
"Yes I think there's a chance of that (retiring after the Australian Open) for sure because I'm not sure I'm able to play through the pain for another four or five months."
Murray had surgery on his hip last year, but will require a second operation to fix the issue.
"I told them (his team) I think I can get through this until Wimbledon. That's where I'd like to stop playing, but I'm also not certain I will able to do that."
The two-time Wimbledon winner will likely be the first of the 'Big Four' to retire, despite being the youngest member of the foursome (he is seven days younger than Djokovic).
Murray and Djkokovic are both 31, Nadal is 32, and Federer is 37.
Federer will likely be the next to retire from the sport, despite his continued success, but Djokovic is still at the very top of his game.
The Serbian lost just three times between winning last summer's Wimbledon title and the end of 2018, and will be the man to beat in Melbourne next week.
Nadal - who has won 18 Grand Slam titles - has withdrawn from 18 of his last 19 hard court tournaments, and has also had some significant injury issues, particularly with his knees and ankles.
His 2018 ended prematurely due to an ankle injury which required surgery, and he was contemplative when talking about Murray's retirement.
"It seems like he had not a very long career but he's 31," Nadal said.
"Ten years ago, if he retired at 31, we will say he had a great and very long career. We will miss him.
"But today it's him, tomorrow another one. We are not 20 anymore. Our generation, everyone is more than 30."
The "Changing Face of Tennis"
After losing to Roberto Bautista Agut in the Qatar Open earlier this month, Djokovic spoke about the "changing face of tennis",
“There’s a new generation of players,” he claimed.
“Nadal and Federer are still there, (Andy) Murray and (Stan) Wawrinka are coming back, Zverev is the leader of this ‘Next Gen’.
Djokovic rates Zverev - who lost the aforementioned mixed doubles final in the aforementioned Hopman Cup final - as the most talented of the rising stars, but also mentioned several other candidates.
“There’s always a possibility and rightfully we’re kind of expecting them to be Grand Slam winners soon," the Serb said when asked about the next generation's prospects of winning Grand Slams in 2019.
"Number one is Zverev obviously, who has been now top-three in the world for a couple of years in a row, winning London, winning I think three Masters 1000 events.
“He’s definitely the leader of the up-and-coming stars and the next generation. You have guys like Tsitsipas, (Dominic) Thiem, Khachanov, (Borna) Coric, these guys are showing that they’re able to challenge the top players for the top titles of our sport so for sure I’m expecting them to do well this season.
“How well? We’ll see.”
Interestingly, three of Djokovic's last four defeats - with the exception of his loss to Bautista Agut - have come against opponents aged 22 or less.
Zverev, Stefanos Tsitsipas, and Karen Khachanov got the better of the world number one last year, and all three have been tipped for big futures.
The Pretenders
Djokovic rates Alexander Zverev as the leader of the next crop of superstars, and it's not hard to see why.
The 21-year-old shocked Djokovic in the ATP Open final in London back in November, and Zverev has also won three of his last six clashes with Federer.
"There's a lot of similarities in terms of trajectory of professional tennis, in our careers," Djokovic said after the ATP Open final.
"Hopefully he can surpass me. I mean, I sincerely wish him that."
Tennis is in Zverev's blood. Both of his parents were professional tennis players, and his older brother Mischa is also a pro.
Standing at 6"6, Alexander has 10 titles under his belt already, but has yet to make a real impact in the Grand Slams, having only made it past the fourth round once.
However, he is tipped for big things in 2019, and is expected to thrive under the tutelage of Ivan Lendl.
He is already ranked as the world's number four, and don't be surprised to see him replace the departing Murray in 'The Big Four'.
Unfortunately, the German is facing a race to be fit for the Australian Open as he recovers from a hamstring injury.
Stefanos Tsitsipas is also a great prospect.
The Greek talent is a tender 20, but is already ranked at 15 in the world rankings after climbing rapidly from 91st.
Like Zverev, Tsitsipas has already beaten Djokovic, and lost two finals to Nadal last year.
The Athenian - whose mother was also a professional tennis player - became the youngest player to defeat four top ten opponents in a single tournament at the Canadian Open last year.
Tsitsipas has won one ATP final to date, the Stockholm Open, was named the ATP Most Improved Player for 2018.
The 20-year-old entered the Sydney International as the number one seed this week, but suffered a surprise defeat to Andreas Seppi in the quarter-finals.
Despite the setback, Tsitsipas will be hoping for a big performance at the Australian Open.
Karen Khachanov is another exciting young talent.
The 22-year-old won three major titles in 2018 - ATP World Tour Masters 1000 Paris, Moscow and Marseilles.
Khachanov also beat Djokovic in the ATP final in Paris last year, and is ranked as the world's 11th best player.
The Russian has fearsome power, and will be looking to improve on making the fourth round at Roland Garros and Wimbledon last year.
He won his first ATP title at the 2016 Chengdu Open, and his second at Open 13 in Marseille in 2018.
Khachanov then won the Kremlin Cup and his first ATP Masters 1000 title at the Rolex Paris Masters before the end of the year.
He has won four titles to date, and will be looking to add significantly to that tally in the coming years.
Khachanov's compatriot Daniil Medvedev is also one to watch.
Also 22, Medvedev is ranked 16th in the world.
The Russian won all three of his titles in 2018, going all the way in Tokyo, Winston-Salem and Sydney.
He decided not to defend his Syndey title this week in order to be fresh for the Open next week.
Completing the list is Croatian Borna Coric.
Ranked 12th in the world, the 22-year-old has two titles to his name thus far.
He announced himself to the world by beating Federer in the ATP final in Halle, and also made his maiden Masters 1000 final appearance this year at the Shanghai Masters.
Coric has lost all four of his previous matches at the Australian Open, but will be aiming to turn his fortunes around this year.
The Croatian star favours hard courts and has a superb serve.
Austrian Dominic Thiem (25), Britain's Kyle Edmund (24), and South Korean Hyeon Chung (22) are also ones to watch.
According to Boris Becker, Zverev, Khachanov, Tsitsipas, and Coric are all "knocking on the door very loudly".
"Zverev looks like the best of the rest," the former great said.
"He is catching up, his victory at the ATP Finals, beating Federer and Djokovic back to back was huge, but equally Khachanov winning the Paris Masters, Tsitsipas's performances throughout the year, Coric's performances again.
"They're knocking at the door very loudly, and eventually it will blow open.
"There's certainly something in the air, that the young guys are going to break through at the grand slams - especially this year."
The future of the sport looks extremely bright, but the old guard will be in no hurry to hand over the reins to the emerging young guns.
Federer and Djokovic will both be hellbent on securing record seventh title in Melbourne, and they remain the two to beat.
2019 may see the next generation make their marks on the Grand Slam, and the Australian Open would be a good place to start.