Iga Swiatek blasted the intense tennis schedule as she announced she will not feature in the Billie Jean King Cup finals in November.
The world number one has criticised the calendar, highlighting that she is expected to travel to Glasgow, where the competition will be held, the day after she concludes the WTA finals in Texas, which has a six-hour time difference.
"I'm disappointed that tennis governing bodies didn't come to an agreement on something as basic as the calendar of tournaments, giving us only one day to travel through the globe and changing the time zone," Swiatek revealed on Instagram.
"The situation is not safe for our health and could cause injury.
With the tennis schedule formatted as it is currently, the 21-year-old would have contested the season-ending WTA Finals from 31 October in Fort Worth, Texas, to 7 November. And then she was expected to fly to Glasgow and compete in the Billie Jean King Cup finals, organised by the International Tennis Federation, the following day on 8 November.
Swiatek said: "I was thinking it through a lot and discussing it with my team, but I will not be able to play at the Billie Jean King Cup in Glasgow.
"It makes me sad. I'm very sorry, because I play for Poland whenever it's possible and I always give it my best.
"Playing in Poland this year [in the qualifiers] was an honour and I hoped to do this again at the end of the season."
Swiatek claimed her first US Open title last month following her second Grand Slam win at the French Open in May to take her career majors haul up to three.
She also conveyed her plans to take this up with the governing bodies, adding: "I'm going to talk to the WTA and ITF in order to change something. This situation is difficult not only for the players like me, but mainly for the tennis fans that support our sport."