Federal prosecutors have told a judge they will let her know within hours whether they will appeal her ruling barring key evidence in Barry Bonds' perjury case.

U.S. District Court Judge Susan Illston said Friday that such an appeal will most likely lead to a delay in the start of the slugger's trial, which is scheduled to begin Monday.

Prosecutors said they would let Illston know by 3 p.m. Pacific time whether they will appeal her ruling to a higher court.

Illston has barred prosecutors from showing jurors three positive steroid tests they allege belong to Bonds, as well as so-called doping calendars investigators say Bonds' personal trainer Greg Anderson maintained for the slugger.

At the same hearing Friday, Anderson renewed his promise not to testify at Bonds' trial.