McCormick, then pastor of Sacred Heart parish in Bridgeport, Montgomery County, was one of 26 Roman Catholic priests suspended in March 2011 for possible inappropriate conduct with children.
None of the allegations involving his suspension by the Archdiocese of Philadelphia is the subject of the trial.
McCormick was arrested by the District Attorney's Office on July 26, 2012, after the alleged victim, now an adult, came forward and said he had been assaulted. Prosecutors said the alleged victim - who was unknown to Philadelphia church officials - was encouraged to press charges by news coverage of church and Pennsylvania State University sex-abuse scandals.
Although the alleged victim came forward months earlier, McCormick was arrested just two days after Msgr. William J. Lynn was sentenced to three to six years in prison. Lynn, 62, was the first church official convicted in a supervisory role for covering up sex assaults by deviant priests.
Lynn's conviction was overturned in December. He is now out of prison on house arrest while the District Attorney's Office appeals the reversal to the state Supreme Court.
Ordained in 1982, McCormick had been pastor at Sacred Heart six years when he was suspended. He had previously served at St. Adalbert's in Northeast Philadelphia and St. Bede the Venerable in Holland, Bucks County.
Before Bright imposed the gag order on Monday, defense attorney William J. Brennan Jr. complained about the archdiocese's weekend announcement of the suspensions of two more priests - the Rev. James J. Collins and the Rev. John P. Paul - for substantiated claims of sexually abusing minors more than 40 years ago.
"I don't know how they came up with something so ponderous, and to pick the day before jury selection to make this announcement," Brennan told Bright.
Archdiocesan spokesman Kenneth A. Gavin said Monday the announcement about Collins and Paul was "independent of any legal proceeding against Father McCormick. . . . Any announcement regarding the suitability of priests for ministry takes place on the earliest possible weekend after a decision is reached."
Once a jury of 12 and several alternates is selected, Assistant District Attorney Kristen Kemp will begin presenting witnesses in a trial the court estimates will last three days.