There is decent talent in the two deep that can hopefully step up along OL and LB. Not as much worried about the DL. But OL and LB are two spots that get better with more experience, and you can't replace in-game experience. So yea, it'll be an "adventure" next year. That Colorado game early is looming large. I bet it will be played up even more, since you guys demolished them in the Alamo.
Blake Trainor/Grayson Reed battle at one OT spot; hoping Kenyon Green is kept at guard, he is great there; Luke Matthews (the last of the Matthews kids) or Layden Robinson at Center (whoever wins that competition for starting spot should be pretty decent); Bryce Foster could push for starting at the other OG spot unless Aki or Josh Bankhead step up; and then maybe Reed/Trainor take the other OT spot... unless Jimbo can land a plug-and-play guy from transfer portal-- Jordan Moko (but L$U and Oregon are pushing for his signature too). They probably want the signed class to all redshirt, including Fatheree.
Linebacker is slightly better, but that's where you need a brains and brawn-- disciple to stay the lane or shadow a mobile QB, never take a penalty, etc. Buddy Johnson excelled in all of that, but as we know so well, these things have to be learned and most often come with experience. Andre White has played some meaningful minutes, but need at least another of the guys to be ready-- one of the 3 4-stars and 2 high 3-stars. And then, one of the safeties often plays closer to the box and next to linebackers... plenty of potentially decent to good options for this spot.
The spring training and fall will be super important with this turnover needing to be sorted out and then starters given time to scrimmage together and gain reps. Covid could screw all that up...