According to this article on espn.com, if Navy wins, we play WMU and if Navy loses, we play Army:
http://www.espn.com/college-football/story/_/id/18189507/conference-bowl-officials-considering-plans-navy-midshipmen-win-american-athletic-conference
ETA: Note that if there are a bunch of upsets, this may change, but that's the plan as of now...both scenarios involve us in the Heart of Dallas