Redshirt freshman quarterback Tristan Gebbia is no longer enrolled at Nebraska.
Gebbia was not at practice, one day after Cornhuskers coach Scott Frost announced he chose true freshman Adrian Martinez as his starting quarterback.
The university did not confirm if Gebbia has asked for or been granted a release from his scholarship.
If Gebbia leaves, Nebraska would have two walk-ons, sophomore Andrew Bunch and freshman Matt Masker as backups to Martinez.
NU opens its season Saturday against Akron.