DC Avalos’ system typically uses three down linemen and a STUD backer on the line plus two inside linebackers, and deploys an additional strongside OLB only in situations when an extra backer is strategically appropriate. In 2019 that OLB role was played by the senior and longtime starter La’Mar Winston, and it did represent a reduction in playing time for him (I thought he handled it gracefully). We therefore didn’t get a clear picture of who the backup and likely replacement was that year, since Winston was ready whenever the position was required.
I believe that, with Winston’s graduation, the job will be filled by his backup from 2018, when the Ducks used a different defensive structure which called for that position on nearly every snap: #29 OLB Jackson.