Prater posted a departure message on his Twitter account.
"I will be transferring," he tweeted. "I love my teammates, SC, my fans, athletic staff. Will always respect the coaches. God Bless."
The 6-foot-5, 215-pound Prater arrived at USC in January 2010 as a highly touted prospect from Proviso West HS in Maywood, Ill. The injury bug hit Prater immediately upon his arrival at USC, and he was forced to redshirt in 2010 with thumb and hamstring issues.
As a redshirt freshman in 2011, Prater received limited playing time as he battled foot and hip injuries during the season. He finished the season with one catch for six yards.
If he transfers to an FBS school, Prater would be forced to sit out the 2012 season as a transfer and would be eligible to play as a redshirt junior in 2013.
Garry Paskwietz is a reporter for WeAreSC.com.