Organisers announced the German's withdrawal on the tournament's Twitter account.
The 27-year-old won her opening match of the tournament on Monday, defeating Ukraine's Elona Svitolina 4-6 6-0 6-3, after coming off a runner-up finish at the Brisbane International on Saturday.
Defending champion Petra Kvitova also pulled out of the tournament with a stomach bug and world number five Agnieszka Radwanska withdrew with a left leg injury.
World number two Simona Halep, who opens her tournament against Frenchwoman Caroline Garcia later on Tuesday, is the top seed at the event.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
(Reporting by Ian Ransom in Melbourne; Editing by John O'Brien)
