Johnny Manziel's girlfriend, Kenzie Werner, says the former Heisman Trophy winner did NOT abuse her ... claiming a post on her social media page Tuesday night that said otherwise was the result of hackers -- and nothing more.
The Instagram Story went up on Werner's IG at around midnight ... and it was extremely disturbing.
The post showed four pictures of Werner with various injuries on her face and her body. In one, she had bruises on her breast. In another, she had blood near her nose.