Up north, the likes of Monfils, Mboko, Eala and Andreescu feature on opening days in Toronto and Montreal.

"Eighteen years of professional tennis. Looking forward to playing in front of you one last time in Toronto," the 35-year-old posted on social media.

The PTPA called the women's and men's tours, the ITF and the ITIA a "cartel, while the four major events—Wimbledon, US Open, French Open and Australian Open—were classed as "co-conspirators".