Trojan safety Josh Pinkard injured his knee while covering a punt late in the Arkansas game.
On Tuesday Pinkard had an MRI that revealed torn ligaments in his right knee. The torn ACL will require surgery that Josh will have done in a few weeks.
The injury will sideline the junior for the season, but he will be able to apply for a medical redshirt.
The Trojans will spend the next two weeks at practice deciding who his replacement will be.