The agreement carries no possible state prison time for Osa Masina, 20, but he could be sentenced to three years in county jail and probation. Prosecutors haven't decided what sentence they'll seek at a hearing in December, prosecutor Donna Kelly said.
Masina was a sophomore linebacker for the Trojans when he was suspended. He no longer attends USC.
Defense attorney Greg Skordas said the plea gives his client a chance to "pick up the pieces" at some point. Masina won't be listed as a sex offender.
His accuser's attorney, Bethany Warr, said the guilty pleas to three counts of sexual battery are "grossly disproportionate" for what she called a violent sexual assault. The agreement was the best prosecutors could do after Judge Keith Kelly excluded key evidence, she said.
Masina was initially charged with rape and two counts of forcible sodomy, all felonies. His accuser testified that Masina assaulted her after edible marijuana and alcohol left her nearly unable to move at a July 2016 party in the Salt Lake City suburb of Cottonwood Heights.