The 2013 runner-up struggled in her first round match on Monday, taking two hours to overcome Croatia's Donna Vekic in three sets, and admitted after the match that it had been almost impossible for her to serve effectively.
"It was pretty obvious I wasn't able to serve in the second and third sets," she said on Tuesday.
"I love the tournament so much, especially after last year playing in the finals. I wanted to do better this year. I tried everything and won the match yesterday and was hoping it could get better overnight, but unfortunately it didn't.
"Now the first plan is for me to get healthy again. I will see my doctors at home and make plans from there."
Lisicki's second round opponent, Czech Andrea Hlavackova, now advances to the quarter-finals.
Second seed Svetlana Kuznetsova also later withdrew, citing a left hip injury and allowing Julia Goerges a walkover into the quarter-finals.