Legitimate concerns about revenue share and workload or a push for control and money? A players association co-founded by Novak Djokovic has filed legal action aimed at disrupting the structure of tennis. Nick Kyrgios is among the signatories. Just what the group hope to achieve is a matter of interpretation. Who's behind the Professional Tennis Players Association and what's their end game? Featured: John Millman, tennis veteran and ex-ATP player council member.

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