The German world number 10 had withdrawn during last month’s Madrid Open and missed the subsequent event in Rome due to food poisoning.
And her return lasted just 36 minutes on Monday before she retired from her match against Kazakhstan’s Yulia Putintseva after losing the first five games.
There was better news for the home fans as compatriot and second seed Angelique Kerber advanced with a solid 7-5 6-4 win over Sweden’s Rebecca Peterson.
And third seed Sabine Lisicki also raised home spirits as she beat Silvia Soler-Espinosa of Spain 6-4 7-5 in just under one-and-a-half hours.
Slovakian fifth seed Anna Karolina Schmiedlova was the only other significant casualty on the opening day as she crashed 6-2 6-1 to Misaki Doi of Japan.