England internationals Joe Marler and Owen Farrell have both been cited over incidents that occurred while they were on European duty with their clubs over the last few days.
Harlequins prop Marler appeared to kick Grenoble hooker Arnaud Heguy in the head on Friday night during the London club's 30-6 victory at The Stoop that sent them into the European Challenge Cup final.
Saracens centre Farrell is alleged to have committed a dangerous tackle on the Wasps scrum-half Dan Robson on Saturday as Sarries reached the Champions Cup final with a 24-17 win at the Madejski Stadium.
A statement on Monday from European Professional Club Rugby (EPCR) also revealed Wasps prop Simon McIntyre had been cited for allegedly kicking Saracens second-row Maro Itoje during the contest.
Marler was on Friday playing his first game back after his two-match ban for his ''Gypsy boy'' slur against Wales' Samson Lee in the Six Nations.
Regarding the 26th-minute tussle with Heguy on Friday, Quins boss Conor O'Shea said: ''Should he do it? No. Is it a red card? No.
"We never condone it but if that is a red card there's a heck of a lot of things that happen on the pitch that are worse.
''When you're a marked man you're a marked man.
''People probably look more for things when Joe Marler's involved than with others, but that's life.''
If Marler is found guilty, the low-end punishment is a four-week suspension, with that doubling for a mid-range ban, while the top-end punishment is a year.
In the case of Farrell, who was shown a yellow card on Saturday for his tackle on Robson, the minimum ban is two weeks, with the mid-range punishment six weeks.
It has left Marler and Farrell sweating ahead of their clubs' finals - Harlequins meet Montpellier in the Challenge Cup on May 13, while Saracens take on Racing 92 in the Champions Cup the next day - and England's June tour to Australia.
The dates of the disciplinary hearings for Marler, Farrell and McIntyre are yet to be announced.
The EPCR statement on Monday also said Itoje had been issued with a warning for playing McIntyre without the ball, and that Grenoble's Fabrice Estebanez had been reprimanded in the same way for striking Harlequins wing Marland Yarde.