Larimore suffered a concussion after a few days of fall camp. It came just four months after he experienced a concussion in April's spring practice.
Sources are indicating that the two successive concussions led Larimore to the medical retirement.
Larimore was expected to start his senior season at inside linebacker. He's had a series of injuries since he came to UCLA, and was considered one of the best linebackers on the team since his redshirt sophomore season.