Williams sustained the injury while diving to make a tackle on Patriots wide receiver Julian Edelman. Williams appears to hit his head against Edelman’s back, then slams his upper body against the field.
The Patriots scored a touchdown on the play. Williams was down on the field for several minutes before eventually being taken off in an ambulance.
Williams was a second-round pick of the Bills in 2011. He had one interception in 15 games last season.
– Rohan Nadkarni