Rangers' Europa League rivals Porto have been charged by UEFA after racist chants were picked up by broadcasters in their 2-1 win over Young Boys.
The Portuguese giants are favourites to top Group G and host Rangers on match day three - October 24.
But they could face a partial or even full stadium closure for the tie after UEFA launched a probe into the alleged racist behaviour of their fans.
It was reported that Young Boys player Jean-Pierre Nsame was the target of sick taunts before he took a penalty to give the Swiss side an early lead.
UEFA say their discipline panel will judge the case next Thursday just a month before Steven Gerrard 's side visit Portugal.
But they could be ordered to close part or even all of their famous Estádio do Dragão as UEFA crack down on racism in football.
Cameroon international Nsame, pictured below against Manchester United , is just the latest in a line of high profile players to be targeted.
Earlier this month Cagliari fans were accused of aiming racial insults at Inter Milan forward Romelu Lukaku as he took a penalty in a 2-1 win for his side.
However the Serie A side were cleared after an independent sports judging panel ruled there was not enough evidence for any sanctions.
Rangers will take no supporters to their next Group G match against Young Boys in Switzerland. Ibrox chiefs refused their ticket allocation for the match on October 3 after twice being hit with partial closure of Ibrox for sectarian singing.
UEFA ordered Rangers to close a 3,000 seat section of Ibrox for the play-off with Legia Warsaw and Thursday's clash with Feyenoord as punishment for sectarian chanting against St Joseph's and Legia.
