Play starts at noon on Center Court, 3.30pm elsewhere
Dominika Cibulkova (SVK) v Anastasia Pavlyuchenkova (RUS)
Catherine Bellis (USA) v Daria Kasatkina (RUS)
Elena Vesnina (RUS) v Anna Blinkova (RUS)
Monica Niculescu (ROU) v Maria Sharapova (RUS)
Mona Barthel (GER) v Agnieszka Radwanska (POL)
Naomi Osaka (JPN) v Katerina Siniakova (CZE)
Ons Jabeur (TUN) v Ying-Ying Duan (CHN)
Ekaterina Makarova (RUS) v Shuai Zhang (CHN)
Lesia Tsurenko (UKR) v Mihaela Buzarnescu (ROU)
After suitable rest
Shuko Aoyama (JPN) / Katarina Srebotnik (SLO) v Anastasia Pavlyuchenkova (RUS) / Olga Savchuk (UKR)
Mona Barthel hopes for a first victory over Agnieszka Radwanska, having lost both their previous meetings. Radwanska prevailed in Montreal six years ago and again in Beijing in 2015.
Dominika Cibulkova and Anastasia Pavlyuchenkova meet for the 10th time on the WTA tour. The Slovakian leads their head-to-head 6-3, including four wins in their last five encounters - the most recent coming in New Haven last year. She also won against Pavlyuchenkova in Doha last season.
Maria Sharapova meets Monica Niculescu for the first time, while Naomi Osaka and Katerina Siniakova also clash for the first time on tour.
Dominika Cibulkova made the semifinal in Doha last year, losing to Karolina Pliskova in three sets.
Ons Jabeur seeks a first victory in Doha, having lost in qualifying in the last two years and in her opening-draw proper match in 2015, 2013 and 2012.
Agnieszka Radwanska has reached the semifinal stage in Doha five times - losing in the last four in 2008, 2012, 2013, 2014 and 2016.
Maria Sharapova has reached at least the semifinal in each of her three Doha appearances - winning the event in 2005 and 2008 and exiting to Serena Williams in the last four in 2013.