According to reports, Johnson suffered the injury during 7-on-9 drills with the defensive line, linebackers and running backs. During the last play of that drill, Johnson collided with running back Terrell Watson, writes ESPN NFL reporter Coley Harvey:
During the play, undrafted rookie Terrell Watson was running the ball when players collided like normal on running plays. Suddenly, Johnson went down.
After being evaluated on the field by trainers for a few moments, Johnson walked gingerly to a nearby cart under his own power. He was taken into Paul Brown Stadium for further evaluation.
Watson is an undrafted free agent acquisition and a bruising 245 pounder Cincinnati signed out of Azusa Pacific.