"A federal judge in San Francisco won't reveal the names of jurors in the Barry Bonds perjury case until the trial is over.

In a ruling Monday, U.S. District Court Judge Susan Illston said she was concerned that "jurors could be approached or even harassed or offered money to provide information about themselves or the case" if their identities were disclosed, as is routine in American trials.

Bonds goes on trial Monday, accused of lying under oath about his use of steroids. The former Giants star says he never knowingly took banned drugs. He has pleaded not guilty.

In her ruling, the judge said she also wanted to prevent jurors from learning about the existence of "various documents" that she has barred from the case. That is a reference to a set of doping calendars that the government says shows Bonds' longtime use of steroids. The material was barred because Bonds' trainer, Greg Anderson, who maintained the calendars, has refused to testify."