Bennett replaces injured starter JT Daniels, who is suffering from an oblique injury, ESPN analyst Robert Griffin III told The Paul Finebaum Show on Friday.
Despite the injury, Daniels had been trying to convince the training and coaching staff to let him play, a source told ESPN's Mark Schlabach.
Redshirt freshman Carson Beck had also been a candidate to start the Bulldogs' home opener.
Bennett started five games last season for Georgia before suffering a shoulder injury. But it was Beck, a four-star recruit from Jacksonville, Florida, who took most of the snaps with the first-team offense in practice this week.
Earlier this week, coach Kirby Smart called Beck the team's No. 2 quarterback, despite the presence of the more experienced Bennett.
"Carson's been our No. 2 quarterback, he's worked with the twos and has worked a lot [with the first team], taken a lot of reps," Smart said. "Stetson still gets some reps from time to time but he's got a lot of bank reps so we ask him to do a lot of things mentally to be prepared and ready to go."