Sale and England wing Denny Solomona has been charged after allegedly directing homophobic abuse at a Worcester player on Saturday.
Microphones picked up Warriors fly-half Jamie Shillcock raising the issue in the 55th minute of the Sharks' win.
Shillcock's complaint is understood to relate to a "homophobic slur".
The BBC has learnt the word Solomona is alleged to have said is similar to that used by Mathieu Bastareaud in a European Cup match in January.
The French centre was subsequently banned for three weeks after his initial punishment was halved because of his guilty plea.
Solomona, 24, has been charged with "conduct prejudicial to the interests of the union or the game" after the incident in the Premiership match.
He will face a disciplinary panel on Thursday, 5 April and faces a minimum suspension of six weeks if found guilty.
Both Sale director of rugby Steve Diamond and Worcester counterpart Alan Solomons said after the game that they had not seen or heard the incident.
Solomona, capped twice at Test level, was sent home early from an England pre-season training camp in August 2017 because of "team culture issues", which were understood to be alcohol related.
He was recalled to the England squad for their Six Nations contest against France earlier in March, but did not feature in the game.
BBC Radio 5 live rugby reporter Chris Jones
My understanding is Solomona is alleged to have used an offensive term identical to the one used by Bastareaud, and if this allegation is proven it will see the England winger face a ban that may not see him play again this season.
Shillcock and Solomona are believed to have made up after the game with Shillcock accepting an apology, but given the complaint was heard over the referees microphone, the Rugby Football Union were duty-bound to investigate.
En resumen, Solomona llamó "maricón" al apertura de Warriors, Jamie Shillcock. Por ello se enfrenta a 6 semanas de suspensión como mínimo; al parecer ya le pidió disculpas a Shillcock y este las aceptó pero como los micrófonos captaron la queja se investiga igualmente.