Gebbia seems to have that "it" factor, as was mentioned in this thread previously, that you just can't coach. He's quick, he throws really well, and he can make fast decisions, which are all things Frost's offense dictates that you have to do. I think right now its his job to lose, and Martinez is probably going to be his back up if not just redshirt.
Downside: Gebbia seemed a little scrawny last year. However, a year in the program lifting, eating, and being around a bunch of other athletes, plus turning 19, will no doubt have helped him grow a bit. On top of that, I wouldn't say that Mackenzie Milton was a Greek statue of an athlete; he was kind of skinny-looking and quick, much like Gebbia. Here's hoping the best for the team, as skill positions like QB, WR, and RB are now VERY loaded and ready for some serious competition!