If you read the USC press release last night, it stated new offensive line coach Tim Drevno “has been Jim Harbaugh’s offensive line coach for 9 years at 3 stops.”
So why would he leave if he was the San Francisco 49ers’ offensive line coach? Well, maybe it becomes clearer when you realize he is actually the “co-offensive line coach” with Mike Solari.
So Drevno will now actually be solely in charge of coaching an offensive line. That makes a little more sense to leave Harbaugh and join Steve Sarkisian at USC.