Marat Safin slumped to a 6-1 6-4 defeat at the hands of world number 512 Wesley Whitehouse of South Africa at the ATP Indianapolis Open.
Safin feels he is "not close to his tennis"
"I never felt comfortable on the court," said Safin, who has won two Grand Slam events.
"This kind of a loss hurts. I don't really know what to do. You can only look for better times. I'm not even close to my tennis."
Whitehouse said: "You never know with him, he can play really well or badly."
Safin's last victory came in the first round at Wimbledon when he beat Britain's Greg Rusedski.