San Diego Chargers wide receiver Eddie Royal was driven off the pitch in an ambulance following an awkward landing during pre-season training.
Royal landed heavily on his back while making a catch before walking over to the team's medical staff, who gave him treatment and appeared to administer oxygen.
The 27-year-old was then put on a stretcher before an ambulance drove onto the field to take him away.
Royal was sitting up when he was loaded into the ambulance, easing concerns that the injury is too serious.
Coach Mike McCoy also played down worries over the severity of the injury, insisting that he was only taken to hospital as a precaution.