Jersey Rugby Club have suspended second row Nathan Hannay for two weeks following a red card against Cambridge.
The former Launceston forward is alleged to have headbutted an opponent.
Hannay is expected to appear before an RFU disciplinary committee before the end of the month.
"While not wishing to prejudice the forthcoming proceedings, Nathan has pleaded guilty to the charge of foul play," said Jersey Rugby Club chairman Bill Dempsey.
"JRFC feel that the best way to deal with the situation is for Nathan not to be part of the Jersey squad during this period," Dempsey added.
The decision to invoke an immediate suspension was made at a meeting attended by Dempsey, Jersey head coach Ben Harvey and Channel Islands' disciplinary officer Cliff Chipperfield.