A scary moment unfolded at New England Patriots practice on Monday ... when defensive coordinator Terrell Williams -- who recently returned from health issues -- suffered an apparent medical scare on the sidelines.
The incident went down on the training fields behind Gillette Stadium, where Williams -- who was hired in January -- suddenly went to the ground, according to reporters on the scene.
Several spectators shared photos on social media showing Coach Williams on the grass as medical personnel provided aid and rolled out a stretcher.