A win for Julia Goerges against Petra Kvitova and a loss for Kristina Mladenovic in the second semifinal will secure the German's Top 10 debut on Monday. Should it come to pass, Goerges would join No.9 Kerber inside the world's elite, marking the first time two Germans would rank in the Top 10 since September of 1997.
Daria Kasatkina loves playing on home soil - she'll contend her fifth career WTA semifinal against defending champion Kristina Mladenovic, and four of her appearances have come in Russia.
Speaking of Mladenovic, the Frenchwoman keeps coming back to St. Petersburg; she's reached the semifinal in two of her three appearances, and is one of five players to have played in all three editions of the St. Petersburg Ladies Trophy (Dominika Cibulkova, Jelena Ostapenko, Roberta Vinci and Kasatkina)
The winningest active player on indoor hardcourts, Kvitova has been in devastating form in Russia, tallying wins over Elena Vesnina, Irina-Camelia Begu and Jelena Ostapenko to make her first semifinal of the season. Kvitova’s win over Ostapenko was her 62nd career win on indoor hardcourts.
After snapping a 15-match losing streak this week, Mladenovic is looking to win three consecutive matches for the first time since she finished runner-up to Simona Halep at the Mutua Madrid Open last May.
Kasatkina is the only Russian to reach the semifinals this week, after being one of seven total to start the tournament in the main draw.
ORDER OF PLAY
SIBUR ARENA (starting at 2 p.m.)
 Julia GOERGES (GER) vs [WC] Petra KVITOVA (CZE)
Not Before 3:30 p.m.
 Daria KASATKINA (RUS) vs  Kristina MLADENOVIC (FRA)
 Gabriela DABROWSKI (CAN) / XU Yi-fan (CHN) vs Timea BACSINSZKY (SUI) / Vera ZVONAREVA (RUS)
KVITOVA leads GOERGES 2-1
(haven't played since 2013; the pair have split their meetings on indoor hard)
MLADENOVIC leads KASATKINA 1-0
(lone meeting came in the third round of the US Open in 2015; Mladenovic won in straight sets)