The NFL is looking into whether the Buffalo Bills violated league rules on reporting injuries in connection to defensive end Jerry Hughes revealing he played with torn wrist ligaments. 

Hughes didn't miss a game but revealed the severity of the injury in a note Tuesday on his Twitter account. 

Hughes was listed on the injury report for having rest days and a groin injury, but the wrist injury was never identified. 

A message left with the team was not immediately returned. 

NFL policy notes a player with a significant injury must be listed even if he fully participates in practice.