Saracens number eight Billy Vunipola has been cited for allegedly striking opposition centre Matthew Tait during his side's 22-6 win over Leicester Tigers last weekend.
The England international appeared to hit Tait with his head in the game at Allianz Park, which extended Saracens' unbeaten run to seven games.
The 22-year-old will face a three-man panel in London later today, and he could face a ban for the incident.
He could miss Saracens' European Champions Cup semi-final against Clermont Auvergne on Saturday.
