Chargers wide receiver Steve Johnson was carried off the field Sunday and into the locker-room after going down in pass drill.
Johnson, who applied no pressure to his right leg as he was carried off, was examined by trainers for several minutes before he was taken inside.
The injury occurred on a simple out pass from Philip Rivers.
Johnson made a diving catch after he and cornerback Brandon Flowers converge fast on the ball.
After getting to his feet, Johnson staggered forward and fell to the ground.
Several teammates surrounded him, including Antonio Gates, Jason Verrett and Manti Te'o.