Johnny Manziel's training for his comeback in the most Johnny Football way possible ... by hitting the beach with an Instagram model and throwing the pigskin!!
The 29-year-old ex-NFL quarterback touched down in South Beach on Tuesday ... just days after he told TMZ Sports he's returning to the gridiron for Fan Controlled Football.
Johnny certainly looks serious about the comeback ... 'cause he brought along a ball as he caught some rays with a bikini-clad Kenzie Werner.