I was thinking that, but it was illness rather than injury, she had her blood pressure taken and the commentator mentioned headaches, possibly heat related, so you'd think she'd be more likely to play tomorrow than if it was injury related.
On a side note, shout out to Nina Stojanovic who has had a superb few months. She returned from a 5 month layoff at the Bolton W25 earlier this year (April), and then played Sunderland W25, but faced a couple of decent opponents, so didn't really do much. She then went on to that W60 event in Spain and lost a tight 3 setter with Katy, 7-5 in the third - I think she may have served for it, or even had MPs iirc, but Katy went on to take that title. So the week later, Katy, then ranked 236, headed to Japan, but has won 2 matches and has barely played since, and subsequently back outside the top 300, whereas Nina headed into her next event ranked 251, and since then she beat Riske on her way to WTA Nuremberg QF (via qualifying), won a European clay W60, reached WTA Jurmala QF (again via qualifying) beating the top 50 4th seed Sasnovich, reached the USO FQR where she had a 6-3 6-6 (*5-1) lead over Taylor Townsend (and we all saw what she did in the main draw) but couldn't see it out. She headed to China and won a W60 last week, and this week she has beaten the 2nd seed Wang Yafan to reach the QF here, her 3rd WTA QF in recent months, and she should now be at a career high. She's won 30 matches since losing to Katy.