Swiss legend Roger Federer on Wednesday pulled out from the inaugural ATP Cup in January for "family reasons".
According to a BBC report, Federer's decision means Switzerland can no longer qualify for the 24-team event.
"It pains me to not be a part of the most exciting new event on the calendar, but this is the right thing to do if I want to continue to play for a longer period of time on the ATP Tour," Federer was quoted as saying by BBC.
"I have decided that the extra two weeks at home will be beneficial for both my family and my tennis," he added.
Earlier, Federer also withdrew from the Paris Masters. The 38-year-old, who won a record-extending 10th Swiss Indoors Championship title on Sunday, said that he is looking to keep himself fit for the ATP Finals that will be held in London from November 10-18.