No.2 seed Anastasija Sevastova has reached the final of every edition of the Mallorca Open to date, winning the title in 2017 and coming runner-up to Caroline Garcia in 2016 and to Tatjana Maria in 2018. Her only previous encounter with Ajla Tomljanovic was during last year's run, with the Latvian winning their quarterfinal 3-6, 6-3, 6-1.
Last year, Sofia Kenin notched up both her first WTA semifinal and her first Top 10 win (over Caroline Garcia) in Mallorca. This year, the No.7 seed enters the tournament fresh off stunning Serena Williams to reach the fourth round of a major for the first time at Roland Garros. Kenin leads the head-to-head against Ons Jabeur 2-1, including 7-6(6), 6-3 in their most recent meeting in the second round of Hobart in January en route to the American's maiden title.
Alison Van Uytvanck and Wang Yafan clash for the second week in a row on grass. The Belgian won their 's-Hertogenbosch opener last week 7-6(4), 6-3 - an exact scoreline reversal of their only other meeting, Wang's 6-3, 7-6(4) victory in the first round of the 2016 US Open.
Last year, Samantha Stosur reached her first grass-court semifinal in seven years here in Mallorca. It was the Australian's fourth last-four run overall on grass following Eastbourne 2008, 2010 and 2011; she is yet to reach a final on the surface. Meanwhile, her opponent, No.4 seed Elise Mertens, is bidding for her second quarterfinal showing on grass in her career following her debut on the surface at 's-Hertogenbosch 2016.
ORDER OF PLAY (all courts start 12 noon)
Alison VAN UYTVANCK (BEL) vs WANG Yafan (CHN)
[WC] Samantha STOSUR (AUS) vs  Elise MERTENS (BEL)
Not before 4pm
 Sofia KENIN (USA) vs Ons JABEUR (TUN)
Not before 6.30pm
Ajla TOMLJANOVIC (AUS) vs  Anastasija SEVASTOVA (LAT)
Alexa GUARACHI (CHI) / Sabrina SANTAMARIA (USA) vs Miyu KATO (JPN) / Xenia KNOLL (SUI)
 María José MARTÍNEZ SÁNCHEZ (ESP) / Sara SORRIBES TORMO (ESP) vs HAN Xinyun (CHN) / Fanny STOLLAR (HUN)
[WC] Mona BARTHEL (GER) / Anna-Lena FRIEDSAM (GER) vs Belinda BENCIC (SUI) / Viktoria KUZMOVA (SVK)
 Elise MERTENS (BEL) / ZHANG Shuai (CHN) vs Irina BARA (ROU) / Andreea MITU (ROU)