They will probably delay their matches till Sunday to give them a chance. Beyond that will w/d them
Although at WTA level players can request a late start, they do have to be available to play on the first day of the tournament unless they're competing in the final day's play of the previous week tournament. If they have a match in their existing tournament scheduled on the same day or later than the first match in their next tournament they will be automatically withdrawn from the next tournament. Astra was replaced last night.
Yes, I'm surprised Katie hasn't been replaced yet. She gets 30 points for her next win at Irapuato compared with 4 points here. She needs to stay where she is and be looking to reach the final and then win the tournament.
R32: Heather Watson (GBR) 113 vs Nao Hibino (JPN) 117 (CH 56 Jan 2016) HTH: 2-0 13 Aug 2018 Vancouver BC $100K Hard SF Watson [133] d. Nao Hibino [JPN] [130] 6-2 6-2 8 Jan 2018 Hobart Hard Q2 (1)Watson [74] d. (7)Nao Hibino [JPN] [98] 4-6 7-5 6-3