The Giants reportedly fired general manager Bobby Evans on Monday, according to San Francisco Chronicle's Henry Schulman.
Evans served as San Francisco's general manager for four seasons prior to being removed.
The Giants entered Monday in fourth place of the National League West division with a record of 72-84.
San Francisco clinched its second straight losing season earlier this month. Last year, the club went 64-98, which was tied with the Tigers for the worst mark in baseball.