England lock Dave Attwood and Wales scrum-half Richie Rees have been called to face serious European Rugby Cup disciplinary hearings in Dublin on January 6.
Attwood is charged with allegedly stamping on the face of La Rochelle prop Petrisor Toderasc during Gloucester's Amlin Challenge Cup defeat at Kingsholm on December 19.
Rees was cited after the Cardiff Blues' Heineken Cup defeat by Northampton with allegedly making contact with the eyes/eye area of Saints hooker Dylan Hartley.
If found guilty, both players face extensive bans that could rule them out of the RBS 6 Nations and beyond.
Attwood has already been suspended for two weeks by Gloucester following an internal investigation into the incident, which reportedly left Toderasc initially fearing for his sight.
The 23-year-old made his senior England debut against New Zealand in November and he is considered one of the best tight forward prospects in the country.
But Attwood's hopes of establishing himself in the England team during the Six Nations will be on the line when he faces independent judicial officer Robert Williams at the ERC offices in Dublin.
The disciplinary guidelines dictate that a low-end ban for stamping is two weeks but the top-end suspension is nine, with the maximum of a year.
Rees is likely to face an even longer ban if he is found guilty of gouging Hartley, an offence the International Rugby Board are clamping down on.
The minimum ban is 12 weeks with a maximum of 156.