The lawsuit between the Professional Tennis Players Association and tennis's governing bodies has started, with one of the bodies using the same lawyers as Manchester City.
One of the defendants, the International Tennis Integrity Agency (ITIA), has brought in Freshfields competition law partner Deba Das, Sky Sports News understands.
Das represented Manchester City in the Associated Party Transaction dispute.
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The PTPA, co-founded by Novak Djokovic, acts as a tennis players' union and alleges the defendants operate a cartel to suppress prize money, set an unsustainable schedule and abuse players' rights and well-being.
Along with 11 professional players including Australia's Nick Kyrgios and China's Zheng Saisai, the PTPA has filed proceedings in New York and sent a letter before action in England.
It has also complained to the UK's Competition and Markets Authority (CMA) and the European Commission.
Djokovic himself has not signed up to the action personally, but his PTPA co-founder, Canadian player Vasek Pospisil, has.
The ATP and WTA, who are two of the defendants, deny the allegations, while the International Tennis Federation (ITF) and ITIA have yet to directly address the claims.
The PTPA and ATP are set to appear in a New York Court on Friday and it is understood the union is seeking an injunction to stop the ATP from conducting "improper, coercive and threatening communications" with players.
Sky Sports News has contacted the ITIA, ATP, WTA and the ITF for comment. The story was first reported by The Lawyer magazine.
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