Ulster number eight Nick Williams has been cited for allegedly striking Cardiff Blues outhalf Rhys Patchell during Friday's Guinness Pro 12 game at Ravenhill.

The 31-year-old from New Zealand was sin-binned after the incident in the sixth-minute. Patchell received on-field treatment and spent a night in hospital as a precaution.

Williams is cited under Law 10.4 (a) - Punching/striking. A player must not strike an opponent with the fist or arm, including the elbow, shoulder, head or knee.