The draw has been made for the end-of-season WTA Championships in Istanbul.
World number one Caroline Wozniacki has been drawn in the red group, along with Petra Kvitova, Vera Zvonareva and Agnieszka Radwanska.
The white group has been made up by Maria Sharapova, Victoria Azarenka, Li Na and US Open champion Sam Stosur.
The opening round-robin matches get underway tomorrow.
