Gerron rushed for a team-high 596 yards last season despite missing most of two games because of a concussion. He left Austin Peay's 52-6 loss to Southern Miss last week because of concussionlike symptoms.
"After consulting with medical personnel this week, it was decided it was in Gerron's best long-term interests to conclude his playing career," the school said in a statement Friday.
Austin Peay coach Kirby Cannon added in a statement that "it was mutually decided that enough was enough."
Cannon said Gerron has the option of remaining involved with the team in another capacity.
Austin Peay (0-2), an FCS program, plays Saturday at Vanderbilt (0-2).