Attorneys for Sandusky argued some of the charges against him lacked specificity regarding the times, locations and victims of the alleged abuse, USA Today reported.
Sandusky is charged with 52 criminal counts of sexually abusing 10 boys during a 15-year period.
Sandusky, 68, denies all the allegations.
Judge John Cleland gave no explanation on his ruling Friday.
Sandusky's trial is set to begin Monday in Bellefonte, Pa.