The Serbian star warmed up for the US Open by securing his 80th career title, with a three-set win over Canadian Milos Raonic at the Western and Southern Open in New York on Sunday (NZ time).
The victory came just prior to the confirmed formation of a breakaway players association, which Djokovic has been a driving force in establishing.
The 17-time Grand Slam winner, along with Canadian Vasek Pospisil and top-ranked American John Isner all resigned from the council after they were formally requested to step down by other members, a source said.
