England duo Joe Marler and Owen Farrell have been cited for foul play during the latest round of European matches.
Harlequins prop Marler, playing for the first time since being banned for his "Gypsy boy" insult, has been reported for an alleged kick on Grenoble hooker Arnaud Heguy.
Saracens fly-half Farrell is alleged to have committed a dangerous tackle on Wasps scrum-half Dan Robson.
Wasps' Simon McIntyre faces a hearing for allegedly kicking Maro Itoje.
Marler, who has 42 England caps, returned to the Harlequins team on Friday after being suspended for two games for calling Wales forward Samson Lee "Gypsy boy" during the Six Nations.
Television pictures appeared to show the 25-year-old kicking Heguy in the head in the 26th minute of a 30-6 victory in the European Challenge Cup semi-finals.
Quins director of rugby Conor O'Shea, however, said the incident was "nowhere near a boot" and not worthy of a red card.
If Marler is found guilty, the low end of a ban is four weeks, rising to eight weeks for a mid-range ban and a maximum of a one-year suspension.
Farrell, meanwhile, could face a minimum two-week ban for his tackle in Saracens' 24-17 win over Wasps in the European Champions Cup semi-final on Saturday.
The 24-year-old, capped 40 times, was sent to the sin-bin following the incident.
With a mid-range offence receiving a six-week sanction, Farrell and Marler could be ruled out of England's summer matches.
Eddie Jones' side face Wales at the end of May before a three-match Test series in Australia in June.
Saracens lock Itoje, who made his England debut during the Six Nations, has been issued with a warning for playing Wasps prop McIntyre without the ball in the second half of Saracens' victory, while Grenoble's Fabrice Estebanez has been given a similar reprimand for striking Harlequins wing Marland Yarde.
The dates of the disciplinary hearings for Farrell, Marler and McIntyre are yet to be announced.