Back injury forces world No. 1 out of Kremlin Cup.
Camila Giorgi and Dayana Yastremska are both sitting at career-high ranknings after raising trophies over the weekend.
Stefanos Tsitsipas cooks on court even without a racket.
The American will make her first appearance at the season-ending championships.
The Romanian is ready to test her injured back and lock up the WTA's year-end No.1 ranking.
World No. 5 calls out opponents for excessive towel use.
The German doesn't want to stop his winning ways just because he's in the field.
