It seems like OLB is where there is the least amount of depth on the team.
We're recruiting some big time LBs for 2018. If they're mission kids, we likely won't see them until 2020. Mika Tafua, who was a highly recruited LB several years ago, is set to return right when fall practice begins. Some have predicted he gets moved to the DL. Kavika Fonua is the likely backup this year, but it doesn't seem like he's at the level of Fred or Francis.
I wonder if they move one or two of the RM safeties to OLB. This could be Drew Jensen, Max Tooley, or someone like that.