Breslin will undergo hip surgery.
The senior has missed three of the last four games for the Trojans due to what Orgeron announced as a hip strain. He also missed the Trojans season opener at Hawaii.
"In my 27 years of coaching, Morgan is absolutely one of my favorite players I've ever coached," Orgeron said. "He is a fantastic young man totally dedicated to football. I just loved his attitude, total team player."
Breslin is in his second season with the Trojans since transferring from Diablo Valley Junior College.
In 2012 he was named to multiple All-American Honorable Mention lists.
Breslin could potentially recover in time to return for a postseason bowl game.
Notably absent from Tuesday's practice was sophomore defensive end Leonard Williams.
Williams was not announced on Orgeron's injured list after the workout.
He was missing once again from the practice field on Wednesday, Orgeron announcing him as questionable for Saturday's game at California with a shoulder injury.