Philly.com describes the incident as it happened:
The altercation began after the two were matched up in one-on-ones. Williams and Cooper got into each other’s face and then a few players stepped in and tried to break it up. They were clenched together for several moments until cornerback Brandon Boykin was the first to step in.
Williams had to be forcibly pulled away. The fiery cornerback then walked to a separate field and strolled up and down by himself.
Cooper looked visibly distraught and stayed out of one-on-one drills that involved receivers and defensive backs until DeSean Jackson came over to him. Jackson eventually walked over to Williams and had a conversation.
We have a feeling this won’t be the last time something like this happens.