No.3 seed Polona Hercog, runner-up here to Pauline Parmentier in 2018, is one of three former finalists in this year's Istanbul draw, alongside 2016 champion Cagla Buyukakcay and 2016 runner-up Danka Kovinic. The Slovenian takes on 20-year-old wildcard Berfu Cengiz, who is making her WTA main draw debut, for the first time. Hercog, who did not travel to the USA this month, stretched Simona Halep to a final-set tiebreak in her last outing in Prague.
No.5 seed Heather Watson has won the most recent two of her three encounters against Sara Sorribes Tormo to date. Sorribes Tormo triumphed 6-3, 0-6, 6-1 in the first round of Seoul 2017, but the Briton won a pair of North American hardcourt meetings last year (7-5, 6-4 in the Vancouver ITF W100 final and 6-3, 4-6, 6-4 in the New Haven 125K third round) to move ahead in their rivalry.
No.7 seed Zarina Diyas won her only previous match against Aliaksandra Sasnovich 7-5, 6-1 in the second round of Wimbledon 2015 en route to her second straight fourth-round showing at The Championships. However, since the Tour resumption Sasnovich has been surging, compiling an 8-3 record including wins over Elise Mertens in Palermo and Marketa Vondrousova at the US Open, while Diyas did not win a set in two matches against Ann Li and Bernarda Pera in the US swing.
In qualifying, fast-rising Elisabetta Cocciaretto faces Tereza Martincova for the second time in a final qualifying round in 2020. The Italian 19-year-old, fresh off an impressive run to last week's Prague 125K final, defeated Martincova 6-2, 6-1 to make her Grand Slam main draw debut at the Australian Open in January.
ORDER OF PLAY (all courts start 11am)
Qualifying - [WC] Eugenie BOUCHARD (CAN) vs  Leonie KUNG (SUI)
Not before 1pm
Sara SORRIBES TORMO (ESP) vs  Heather WATSON (GBR)
Katarina ZAVATSKA (UKR) vs Paula BADOSA (ESP)
Not before 7pm
 Polona HERCOG (SLO) vs [WC] Berfu CENGIZ (TUR)
 Zarina DIYAS (KAZ) vs Aliaksandra SASNOVICH (BLR)
Qualifying - Ellen PEREZ (AUS) vs  Harriet DART (GBR)
Not before 1pm
Anna Karolina SCHMIEDLOVA (SVK) vs Kaja JUVAN (SLO)
Jasmine PAOLINI (ITA) vs Stefanie VOEGELE (SUI)
Elixane LECHEMIA (FRA) / Ingrid NEEL (USA) vs Vivian HEISEN (GER) / Emily WEBLEY-SMITH (GBR)
[WC] Ayla AKSU (TUR) / Ipek OZ (TUR) vs Anna DANILINA (KAZ) / Yana SIZIKOVA (RUS)
Qualifying - Dejana RADANOVIC (SRB) vs Olga DANILOVIC (SRB)
Qualifying -  Tereza MARTINCOVA (CZE) vs  Elisabetta COCCIARETTO (ITA)
Not before 2pm
Natela DZALAMIDZE (RUS) / Miyu KATO (JPN) vs Greet MINNEN (BEL) / Alison VAN UYTVANCK (BEL)
Arina RODIONOVA (AUS) / Heather WATSON (GBR) vs  Kateryna BONDARENKO (UKR) / Sharon FICHMAN (CAN)