Novak Djokovic said he would step away completely from the Professional Tennis Players Association, citing concerns over transparency and governance within the organisation.
Travel disruptions following airspace closures in the Gulf have forced Daniil Medvedev and Andrey Rublev to miss an Indian Wells exhibition, while an ATP Challenger in Fujairah was cancelled amid security concerns.
The Australian Open will offer a record A$111.5 million ($74.73 million) in prize money this year and while players welcomed the increase, top names like Coco Gauff and Aryna Sabalenka said the push for a bigger payout must continue across the Grand Slams.
The event comes at a time when tennis is facing criticism over its relentless tour schedule.
While off-court battles over pay and governance rumbled on, opportunities were scarce beyond the duopoly at the top of the men's game, leaving Djokovic to provide the year's standout moments for the chasing pack.
Jannik Sinner and Carlos Alcaraz are among the world's top players calling for the Davis Cup to return to its traditional home-and-away format and be staged over two years, a proposal backed by ATP chairman Andrea Gaudenzi.
Carlos Alcaraz has defended his decision to play in the lucrative Six Kings Slam exhibition event in Saudi Arabia
Novak Djokovic, who claimed his fourth US Open and last major title in 2023, said he has "earned the right" to pick his schedule.'
'We have exhausted all options for reform through dialogue, and the governing bodies have left us no choice but to seek accountability through the courts.'
Carlos Alcaraz distanced himself from the class-action lawsuit filed by the Professional Tennis Players' Association
'I've never been a fan of division in our sport, but I've always fought for better representation and influence of and positioning of the players globally in our sport, which I think is still not where I think it should be.'
Novak Djokovic said a majority of players believe favouritism is at play in the tennis anti-doping system.
Rather than face the prospect of a lengthy ban, with a decision expected by the end of the year, World No 1 Jannik Sinner accepted the three-month suspension which will allow him to return before the French Open.
Simona Halep questioned the "big difference" in how doping cases are treated after world number two Iga Swiatek was handed a one-month drugs ban
'The romanticism of late night tennis in New York, it's time to move past that'
Djokovic backs schedule change at expanded Australian Open
It was sweet victory for Japan's Miyu Kato as she bagged the mixed doubles crown with Tim Puetz after being disqualied from the women's doubles.
Djokovic's players body blindsided ATP player council, says Anderson.
The Serb set up the breakaway PTPA on the eve of the US Open in September and resigned as head of the player council but last month he confirmed that he had been nominated by his fellow professionals for the current elections which he accepted.
'Is he serious? It's a selfish political move to gain popularity.'
After a dominant start, Djokovic struggled in the second set and lost his temper even after closing it out.
Australia's Nick Kyrgios said he supported vaccination "but how we are handling Novak's situation is bad, really bad". The Australian Open begins on January 17, but the multi-millionaire Djokovic is constrained from training as he sits in a hotel where one Iranian detainee said he had found maggots and mould in the bread.
'Everybody knows that they could wait a little bit, no? It was an unfortunate decision.'
World number one Novak Djokovic had enough on his plate already on Wednesday without marauding Russian Daniil Medvedev pummelling him to a shock 6-3, 6-3 defeat at the ATP Finals.