I would place my bets on the Oakland Raiders. Jon Gruden was by far one of Johnny's leading cheerleaders during the whole process leading up to the draft. In 2014 when the Raiders had the #4 pick Gruden urged them to draft Johnny. He also pushed for the Bucs to draft him in an interview stating
"If they pick Johnny Football, I might have to reapply for my season tickets. I would love to see my hometown Bucs take Johnny Football, we need a kid like this to bring juice back to our organization." Here he is on Mike and Mike stating that he is a "
Big fan of his"
http://www.espn.com/video/clip?id=14103301 Right now the clear starter for the Raiders is Derek Carr. Derek has been struggling recently with staying healthy and Greg Olson's new system. His backups are EJ Manuel and Connor Cook, I would expect Manuel to re-sign with Oakland and them to drop Cook after him struggling this past season.
The Raiders have a coach who loves him and a clear need for a consistent QB2 to backup Derek Carr. I think Gruden has the ability and knowledge on how to handle a media storm around a player and to get guys to buy into a system. I think this is the only realistic shot at him getting to play.
But when they eventually move to Vegas..... all bets are off for Billy Manziel