Either the Manatee High product was already there or several of his competitors for the backup role concluded the job was his to lose.
Multiple sources, including ESPN and the Omaha World Herald, reported Saturday that returning backup quarterback Cody Greene has requested a release from his scholarship and is exploring transfer options.
Green started several games last year after starter Taylor Martinez and Zac Lee were injured and led the Cornhuskers to victories over Iowa State and Colorado.
It was also reported last week that another Nebraska quarterback, Kody Spano, announced he was ending his career because of multiple injuries.
If Green is granted his request, the only two quarterbacks left on scholarship at Nebraska are Martinez and Carnes. A school spokesman said Nebraska head football coach Bo Pelini had no comment on Green.