Somdev made a bright start against his German opponent but lost 6-2 2-6 3-6. (Agencies)
Struff had shocked top seed Mikhail Kukushkin 7-6 (6) 6-2 in the first round.
India's Leander Paes and Rohan Bopanna are competing in the doubles main draw. Paes and his Czech partner Radek Stepanek have been seeded second and their first round opponents are Julien Benneteau and Edouard Roger-Vasselin from France.
Bopanna and his Pakistani partner Aisam-ul-haq Qureshi have been seeded third and they will open their campaign against Dutch player Jean-Julien Rojer and Horia Tecau from Romania.
The tournament is last ATP event before the Australian Open, season's first Grand Slam, starting January 13 in Melbourne.
Somdev made a bright start against his German opponent but lost 6-2 2-6 3-6.