Not a good situation for Nebraska since Frost's system features a running QB and the true freshman starter (Martinez) sat out all of 2017 with a serious shoulder injury. The back-up (Andrew Bunch) is a JUCO transfer with no other major college offers and fairly pedestrian passing stats. The health of Martinez will be top priority this year.
In addition to Gebbia, another highly regarded QB (Patrick O'Brien) transferred this Spring and last year's starter (Tanner Lee) declared early for the NFL draft. Gebbia was widely considered a better passer than Martinez. Nebraska has one of the best WR units in the B10. I'm guessing that Stanley Morgan might already regret his decision to return for his senior year and it could really get ugly if Martinez goes down at some point.
All fair points, but Scott Frost's offense is at its best with a true dual threat QB. The passing game is predicated on the defenses need to constantly account for the QB RPO. Without that threat, its just another Spread offense that can be blown up with relentless pressure at the line of scrimmage.
Stanley Morgan will have more opportunities with a QB like Martinez at the helm.