The Australian Open hasn't even started and already Melbourne has produced shock waves with the impending retirement of Andy Murray.
Serena Williams bids for a record-tying 24th grand slam two years after she won Down Under while pregnant and Roger Federer seeks three in a row in the men's draw.
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But, yes, there's even more than that to look out for ...
No. 2 for Nadal?
Rafael Nadal's lone Australian Open title exactly a decade ago couldn't have been more dramatic.
For a start, Nadal outlasted fellow Spaniard Fernando Verdasco in a five-hour, 14-minute semifinal. Such was the draining nature of the slugfest that Nadal teared up waiting to receive serve on match point.
Back then, Nadal was merely 22 and injuries hadn't taken as much of a toll on his seemingly superhuman body. And sure enough, two days later, he still had enough left to upend Federer in five more sets.
In one of the enduring images in the tournament's history -- at the least -- Nadal put his arm around a crestfallen Federer during the trophy ceremony.
But more recently the 17-time grand slam winner has been the one suffering heartache in Melbourne.
A hamstring injury scuppered his chances of achieving the "Rafa Slam" in 2011; he succumbed to Novak Djokovic in the longest grand slam final of all time a year later; in 2014 a back injury in the warmup of the final rendered him powerless against Stan Wawrinka; and in 2017 in a battle of comebacks, Federer reversed a break deficit in the fifth set of the final to end a 10-year grand slam losing streak to his chief rival.
As if all that wasn't enough, leading Marin Cilic two sets to one in the quarterfinals last year, a hip injury eventually forced Nadal to retire in the fifth set.
Bidding, once again, to become the first man to win each of the majors at least twice, Nadal's prospects this edition don't appear optimal.
An abdominal injury plus ankle surgery delayed his off-season training regimen. Unfit he skipped his second match at an exhibition in Abu Dhabi in December and duly withdrew as the top seed of the Brisbane International with a thigh strain.
That was nothing new: Nadal withdrew or retired from all but one of his hard-court events last season.
"Of course is good news that I am here again," Nadal told reporters Saturday. "Is again another season, coming back from a tough period of time but with highest motivation possible to start another season."
While his health is uncertain, one thing is definite. There won't be a matchup with Federer -- at the top of the men's list with 20 majors -- in the final. In the same half, they could meet in the semifinals.
Sharapova uncertain too
Nadal isn't the lone grand slam champion whose fitness is uncertain returning from injury. Besides Murray, world No. 1 Simona Halep and Maria Sharapova find themselves in similar circumstances.
Sharapova has never been one to throw a "pity party" yet her frustration levels must be high nonetheless.
Arm issues plagued Sharapova throughout 2018, with the five-time major winner subsequently ending her season due to shoulder woes. Eleven years ago a shoulder injury threatened her career and her once potent serve has never been quite the same.
Sharapova's shoulder, however, seemed to hold up well at her first tournament of the season in Shenzhen last week. The sting was noticeable on the serve and there were few double faults.
That was the good news.
Unfortunately for the 31-year-old, a thigh injury prompted a retirement in her high-profile quarterfinal against one of the WTA's breakthrough players of the last year, Aryna Sabalenka.
It's not the preparation the Russian sought as she seeks a first major -- or major semifinal -- following her 15-month drug suspension.
Trouble for Djokovic's rivals?
Djokovic cut a terse figure after losing to Roberto Bautista Agut in the semifinals of his first official tournament of 2019 in Doha.
Based on that, his rivals should be afraid.
Djokovic also came away from the French Open agitated in the wake of a quarterfinal defeat to unheralded Italian Marco Cecchinato -- then turned into the player who dominated men's tennis for the better part of 2011, 2015 and 2016.
He won Wimbledon and the US Open to climb to 14 majors.
Having been upset the last two seasons at the Australian Open, where he is historically the joint most successful men's player alongside Federer, the Serb now appears due for title number seven in Melbourne.
It would complete a stunning turnaround for Djokovic, who underwent elbow surgery about 10 days after his 2018 Australian Open ended at the hands of Hyeon Chung.
A different question for Wozniacki
'When are you going to win a first grand slam?' Caroline Wozniacki has heard that question a lot in her career, especially when the Dane was the world No. 1.
In Melbourne this year, she might be asked: 'What does it feel like to defend a grand slam?'
She no doubt wouldn't mind the latter query.
Twelve months ago Wozniacki won that first major following two defeats at the last stage of the US Open.
When Wozniacki trailed Jana Fett 5-1 in a third set in the second round and stared at two match points, who would have thought it? But the Croatian narrowly missed what would have been an ace on the first match point and so began the Wozniacki comeback that ultimately ended by downing Halep in a thriller.
Wozniacki only exceeded the second round once in her ensuing three grand slams, revealing later she suffered from rheumatoid arthritis.
"Every day is a new day and you feel how you feel," Wozniacki told reporters in Auckland, where she was upset last week by Canadian qualifier Bianca Andreescu.
"But I feel pretty good about it and it's about figuring out what little things work for me work and what makes me feel good."
New look for Venus
In what could have been the most surprising of a slew of coaching changes in the women's game in the off-season, Venus Williams parted company with David Witt.
A former men's pro, Witt began as a hitting partner with the seven-time grand slam winner in 2007 prior to becoming her traveling coach.
On the face of it, Williams' results in 2018 might have prompted the move: Her year-end ranking plummeted from fifth to 40th, largely emanating from being ousted in the first week at all four of the majors. Or is she planning on retiring soon?
"There are so many theories out there but I'm not going to confirm or deny anything," the 38-year-old told reporters in Auckland, where she was also beaten by Andreescu. "I'm just going to shroud it with mystery, try to keep winning matches and everyone will have to wait and see."
How different it was two years ago when Williams reached finals at the Australian Open and Wimbledon, thus coming within one match of picking up a first major since 2008.