It was a well known fact Roach was mute, and commonly communicated with ASL.

However, a running joke has started between him and the team. They call his hand gestures to you DSL - dinosaur sign language.

Funny as it might be, it worked. He could give you a gesture from anywhere on the field and you'd follow through with the needed action, your higher intelligence understanding the references he taught you

As of now, he was trying to teach you a new one, just for fun. Sit.