Sign Up for Sports World News’ Newsletter and never miss out on our most popular stories.

Serena Williams’ withdrawal from next month’s BNP Paribas Open at Indian Wells next month begs the question: Is her withdrawal due to a bad back or continued bad blood?

Williams has not played the Indian Wells, Calif., event since 2001, when her sister Venus pulled out of a semifinals match against her just four minutes before the match was to start. Serena was booed during the final against Kim Clijsters, and Venus and their father Richard were booed even more when they went Serena’s box in the stands.

The family claims they heard racial slurs aimed at them and has boycotted the event ever since.

The Independent reported that Serena had softened her stance toward the tournament after watching the Nelson Mandela biopic Long Walk To Freedom and appeared poised for a return after her name appeared on the 2014 entry list.