Sgt. Lyn Tomioka said the incident occurred in the Marina District at 7:40 a.m., at Retiro and Casa ways.
Tomioka said officers attempted a traffic stop on a four-door Toyota reported stolen out of San Francisco, when the male driver, the car's sole occupant, put the car in reverse and clipped an officer's foot.
The driver then took off, and was last seen heading northbound on Marina Way, possibly toward the Golden Gate Bridge, Tomioka said.
A bridge spokeswoman said today she had no information about any suspect vehicle crossing the span.
San Francisco police decided not to chase the vehicle because of safety concerns due to traffic in the area, but they did notify the California Highway Patrol, Tomioka said.
There was no immediate word from the CHP about whether they participated in a search for the vehicle.
The driver was described as a thin man wearing a blue knit cap. Tomioka said the officer's injury was not serious.