British & Irish Lion Martin Corry faces a lengthy ban after being sent off for Leicester in the first half of their Zurich Premiership game at Saracens.
The number eight was shown the red card by referee Chris White after apparently elbowing Lions team-mate Richard Hill in the 27th minute at Vicarage Road.
Corry will now be hauled in front of a Rugby Football Union disciplinary panel ahead of next weekend's European Cup semi-final with Toulouse.
The RFU guidelines show a ban of three weeks as the "entry point" for striking an opponent with fist, arm or elbow.
That would rule Corry - named in Sir Clive Woodward's squad to tour New Zealand last Monday - out of the semi-final and the Premiership game against Wasps on April 30.
A longer suspension could see Corry, who captained England during the Six Nations Championship when Jonny Wilkinson and Jason Robinson were injured, miss the Zurich Premiership final on May 14 and the European Cup final on May 22.