ORDER OF PLAY
Play starts at 2pm
 M Rybarikova (SVK) v  G Muguruza (ESP)
After 1 Men's singles match and not before 5pm
 A Kerber (GER) v  V Azarenka (BLR)
After 1 Men's doubles match
M Adamczak (AUS) / J Moore (AUS) v A Bogdan (ROU) / E Ruse (ROU)
Angelique Kerber is aiming to reach her second final of 2019, having also reached the finale in Indian Wells, where she lost to Bianca Andreescu. She has twice previously made the final in Monterrey, losing to Anastasia Pavlyuchenkova in three sets in both 2013 and 2017.
Victoria Azarenka is enjoying her best tournament of the year to date, having made the last four for the first time in 2019. This is her first appearance in Monterrey.
Neither Kerber or Azarenka have dropped a set at this year's tournament so far.
Kerber has won just one of her eight previous completed meetings with Azarenka, beating the Belarusian at the Australian Open in 2016. The pair's most recent encounter came later that year in Miami, Azarenka winning the Miami semifinal 6-2, 7-5.
Magdalena Rybarikova is also appearing in the last four for the first time this year, and also for the first time at Monterrey - having previously gone out at the quarterfinal stage in 2014, 2015 and 2018.
Garbiñe Muguruza is another playing in the last four in 2019 for the first time, and is seeking to defend the title she won last year, beating Timea Babos. The Spaniard is hoping to become the first player to defend the Monterrey title since Anastasia Pavlyuchenkova in 2011.
Rybarikova has been taken the distance twice in her three matches this week, while Muguruza was taken three sets once, by Margarita Gasparyan in the second round.
Muguruza holds a 4-2 win record against Rybarikova, including 6-1, 6-1 victories at both the US Open and Wimbledon in 2017.
The last four finals in Monterrey have gone to three sets. Ana Ivanovic was the last straight-set winner, beating Jovana Jaksic 6-2, 6-1 in 2014.
Staying hot and sunny all day, with a maximum temperature of 33C (91F).