Gloucester hooker Olivier Azam, who retires at the end of the season, has been banned for four weeks for headbutting Northampton's Adam Eustace.
The incident occurred when the sides met at Kingsholm on April 19 and the punishment was handed down by a disciplinary committee comprising Rugby Football Union disciplinary officer Judge Jeff Blackett, Robert Horner and Jeremy Summers.
Blackett said: "This was at the lower end of the scale of offending which is four weeks. The panel increased the sanction to six weeks to reflect his poor disciplinary record but then reduced the sanction by two weeks to reflect his genuine remorse, his plea of guilty and his good conduct at the hearing."
He added: "We were also aware that he is likely to retire at the end of this season and may already have played his last game of professional rugby."
Azam is free to play again on May 25, three days before the Aviva Premiership final.
Northampton second row Mark Sorenson also appeared in front of the panel on Wednesday and was cleared of a charge of making a dangerous tackle on Newcastle forward Tim Swinson during his side's 22-15 victory last Friday.