With confirmation that Serena Williams will not play for the remainder of 2017, there is a G.O.A.T.-shaped hole to be filled on the WTA Tour.
The 23-time grand-slam winner confirmed on Wednesday she is pregnant with her first child.
Williams is aiming for a return to competitive action in 2018, having apparently won the Australian Open while carrying her baby if a "20 week" timeline she suggested in a since-deleted Snapchat post is accurate.
The American is likely to spend an entire grand-slam cycle - if not longer - away from the court, so Omnisport's Matthew Scott looks at who is best-placed to fill her mighty shoes as top dog.
Lest we forget, the German is world number one as Williams begins her sabbatical.
@serenawilliams!! You will be such an amazing mother and I wish your family health and happiness for the best journey in the world— Angelique Kerber (@AngeliqueKerber) April 20, 2017
After a difficult start to 2017, Kerber has begun to regain her form and reached a first final of the year in Monterrey last time out.
Kerber fell at the first hurdle at the Madrid and Rome Masters in 2016, as well as the French Open - leaving a glut of rankings points up for grabs if she can get her game together on clay this year.
Don't @ me.
The only player Sharapova has ever suffered a continued struggle against is... Serena Williams.
Sharapova holds career head-to-head advantages over Kerber (4-3), Venus Williams (5-3), Karolina Pliskova (1-0) and Garbine Muguruza (3-0) - each of the non-Serena grand slam finalists since she was suspended from the game.
And with her return from a doping ban coming just as her great rival is stepping away from the limelight, it gives the 30-year-old another motivation ahead of her comeback in Stuttgart next week.
Arguably no player on the WTA Tour currently has as much upward momentum as the world number seven.
In the space of two years, Konta has gone from world number 151 to breaking the top 10, with her sights already set on the very top.
After securing the biggest win over her career against Caroline Wozniacki in the Miami Open final, Konta said: "I play smart tennis and calmer tennis, I think."
Konta's three WTA titles have come in the past nine months and she has only lost one final to date, proving her burgeoning big-game temperament.
With two titles to her name already in 2017 backing up last year's run to the US Open final, Pliskova has risen to a career-best ranking of third in the world, leaving her in pole position to challenge Kerber for top spot for the time being at least.
Like the German, Pliskova will have plenty of points to make up on during the clay season and only a second-round defeat in Dubai blots an otherwise solid copybook from 2017 so far.
Wins over fellow top-10 players in Brisbane, Qatar and Indian Wells suggest the Czech has the appetite for the big occasion.
The Belarussian has as far to go to reach the top as anybody in this selection, Sharapova aside, but Azarenka's progress will be fascinating, once she returns to action after giving birth to her first child.
Today I had my hardest fight and my very best victory! Our son was born healthy and happy! So thankful and blessed! Thank you pic.twitter.com/zsoFRivnvQ— victoria azarenka (@vika7) December 20, 2016
Victories in Indian Wells and Miami last year - which included wins over Kerber and Serena - hinted that the two-time major winner was back to her best.
Azarenka has won seven of her nine career meetings with Kerber and is one of few players in possession of power even remotely similar to Serena.
If the 27-year-old can hit the ground running, it will suggest that Serena can too, so any of the above will have to be quick if they are to make the most of the WTA Tour queen's absence.
|Conte defends Chelsea record compared to Mourinho|
|LaLiga strugglers Espanyol show Flores the door|
|Messi is an alien but Sevilla can bring Barcelona back down to Earth, insists Montella|
|Four in a row for Wigan as Saints thrash Huddersfield|
|Reims´ latest vintage secure promotion to Ligue 1|
|Gloucester cruise into Challenge Cup final|
|Quiros claims one-shot lead despite rollercoaster round two|
|Millwall 0 Fulham 3: Sessegnon on target as Jokanovic´s side go second|
|Curry to begin modified practices on Saturday|
|Ancelotti welcomes Arsenal links, praises Wenger decision|
|Nadal produces ´best match of tournament´ as Dimitrov beats doubles partner|
|I think Arsenal would be good for a German coach - Podolski|
|Wilshere, Ramsey, Mertesacker and the best social media reaction to Wenger´s Arsenal departure|
|Watson haunts Royals with Super Kings hundred|
|Selby bracing himself for tough title defence|
|Exeter left ´disappointed´ by Ampadu transfer verdict|
|Froome thrilled with ´perfect´ build-up to Giro|
|Copa del Rey glory a good way to put European exit behind us, says Valverde|
|LMA hails Wenger´s impact at Arsenal|
|Wenger passes the torch as Arsenal face up to his formidable legacy|
|Gazidis: Arsenal cannot replace Wenger – we need a new path|
|Ronnie rivals never doubted Crucible attendance of ´snooker´s Tiger Woods´|
|Van Bronckhorst using Wenger´s methods at Feyenoord|
|Former NFL lineman Evan Mathis´ 1952 Mickey Mantle card sells for $2.88M|
|Wasps forward Johnson suspended for failed drugs test|
|I´d break another finger to win the Copa del Rey - Rakitic|
|Arsene Wenger: The Arsenal manager´s worst moments|
|Wright: More Arsenal changes needed after Wenger exit|
|Guardiola wishes Iniesta the best ahead of potential Barcelona exit|
|Real football people appreciate Wenger - Moyes, Warnock and more pay tribute|
|Guardiola set for contract talks with Manchester City|
|Controversial Slater score helps Storm to victory|
|Liverpool top, DVDs just invented and no Harry Potter – The world when Wenger joined Arsenal|
|Heynckes cannot compare Lewandowski and Ronaldo|
|Ronaldinho, Ronaldo, Messi, Mbappe and more – the stars Wenger claims he could have signed|
|Ferguson: Rival, colleague and friend Wenger is one of the greatest|
|Gattuso wary of challenge for Milan´s European place|
|Neuer returns to Bayern training after seventh-month absence|
|Wembley no advantage for Spurs in semi-final, warns Mourinho|
|WATCH: Dez Bryant works out with Odell Beckham Jr. as rumors swirl|
|PSG, Monaco, the CSL, France? - Wenger´s possible next moves|
|Rematches, rivalries and a mouth-watering Wembley clash – The pick of the 2018 NFL schedule|
|Wenger ´an example´ to foreign Premier League managers like Benitez|
|Wilshere: Wenger is like a father|
|Guardiola wants Wenger to find new role in football|
|Henry: Wenger´s Arsenal legacy is untouchable|
|Mourinho: Wenger feud shows how much I respect him|
|Conte: Top four still possible for Chelsea|
|Frizell inspires Highlanders win over Blues, Lions beat Waratahs|
|Majestic Nadal hammers Thiem in Monte Carlo|
|Aguero out for the season - Guardiola|
|Wenger´s 22-year Arsenal tenure will not be matched, says Conte|
|Celtic would let Rodgers move to Arsenal|
|Squillaci, Cech & Wenger´s worst signings at Arsenal|
|Heynckes: I cannot imagine Wenger at another club|
|Thank you Arsene - Emery pays tribute to Wenger|
|Fabregas and Van Persie join tributes to Arsenal boss Wenger|
|Smith confirmed as England national selector|
|1,228 matches and seven FA Cups - Wenger at Arsenal in Opta numbers|
|Mertesacker ´emotional´ as Wenger announces Arsenal departure|
|Ancelotti, Tuchel, Henry – Where do Arsenal turn after Wenger?|
|Klopp doesn´t want Liverpool to chase Golden Boot for Salah|
|´The Arsene Wenger Stadium´ - Former Arsenal players call for tribute|
|Wenger was so good ´it was scary´, says Merson|
|Shields requests to be released for England duty|
|Khan: ´Cheat´ Alvarez got off lightly|
|I fell in love with playing for Wenger - Winterburn|
|Van der Sar urges Kluivert to continue Ajax development|
|Cockerill signs Edinburgh contract extension|
|Klopp pays tribute to ´outstanding´ Wenger|