Petkovic made her comeback in a Fed Cup match in April, losing to Samantha Stosur. She then played at the Porsche Tennis Grand Prix in Stuttgart, beating Kristina Barrois in the first round. In her second round match against Victoria Azarenka, Petkovic was down 2–6 and 4–4 when she rolled her right ankle. She was forced out with what was later revealed to be torn ankle ligaments, which required surgery and kept her out for another four months, including the French Open, Wimbledon, and the London Olympics. She said of the injury: "I knew immediately that it was bad because I heard everything crack. I tried to pull my foot up, and it just flopped there. The first thing I thought was: 'Don’t cry. Don’t cry. Don’t cry.' With 4,000 people watching. In Germany." She attended weeks of rehabilitation to rebuild the muscles in her leg, working seven hours a day, five days a week.