Oregon left tackle Tyler Johnstone will miss all of this season with a torn ACL in his right knee, according to CSNNW.com.
Johnstone is scheduled to have surgery on Friday.
Johnstone also tore the ACL in the same knee during last season's Alamo Bowl victory over Texas. He was cleared by doctors to return after rehabbing the injury but felt the knee pop during the team's first week of practice.
Johnstone is a three-year starter on the Ducks' offensive line. Redshirt junior Andre Yruretagoyena will likely replace him. Yruretagoyena has played 11 games at both guard and tackle.