Uefa is set to launch an investigation into incidents during Rangers' defeat by Osasuna in Spain.
Riot police confronted Rangers fans in Pamplona
The Ibrox club's fans clashed with Spanish police and Rangers complained of "heavy-handed policing".
But Rangers could also face sanctions after internet footage which appeared to show some of their fans singing sectarian songs after the game.
A Uefa spokesman said: "It is very likely we will start an investigation regarding this match."
Uefa has received the security officer's report into the game and will soon make a decision on whether either or both clubs face charges.
The spokesman continued: "Now Uefa will look into the matter.
"If an investigation is started this would then be dealt with by the control and discplinary body, at the end of March or beginning of April."
Rangers have complained to the governing body about policing and segregation for the away leg of the Uefa Cup last-16 clash with Osasuna in Pamplona.
Some of the Glasgow club's supporters claimed that riot police charged into their section for no reason, lashing out with sticks, fists and kicks before, during and after the match in Pamplona.
It is very likely we will start an investigation regarding this match
Reports suggest that the Spanish police feel their actions were justified in light of misbehaviour among Rangers' travelling support.
Uefa also confirmed it was "fully aware" of the footage of alleged sectarian singing, less than a year after fining Rangers for discriminatory chanting in a Champions League tie against Villarreal.
And Uefa acting chief executive Gianni Infantino has hinted that Rangers could face sanctions following the crowd problems.
Infantino was in Glasgow for the Uefa Cup quarter-final draw, before he expressed disappointment after fan violence at several recent matches.
"Our disciplinary experts are analysing the report of the match and security delegates," he told BBC Sport.
"And they'll take appropriate measures and sanctions that need approved."
He pointed out that national football associations, clubs, players and fans all had to play their part in protecting the reputation of the game.
"In the last few months and weeks, we have witnessed in several countries problems of violence on the pitch and outside of the pitch and this is not acceptable," said Infantino.
"We have to do something against that and Uefa has already excluded a Dutch club from the Uefa Cup earlier this year because of the behaviour of fans of the club at an away match in France."
Feyenoord were the club on the receiving end on that occasion and Infantino said they would not shirk from penalising other clubs in a similar fashion.
Rangers chief executive Martin Bain has suggested that Uefa had agreed with his club's fears about the poor organisation in Spain.
And Rangers captain Barry Ferguson, who watched the game from the stands through suspension, was critical of the police after witnessing the treatment of travelling fans.
Infantino admitted that there was a need for other countries to follow the UK lead in organising the policing of football matches - and in ticketing arrangements.
But Uefa delegate Manos Mavrokoukoulakis was quoted earlier in the Daily Express criticising Rangers for allowing too many visiting fans to travel to El Sadar Stadium for Wednesday's tie.
"The critical point is that Osasuna gave Rangers 1,400 official tickets and Rangers could not convince other supporters not to travel," he said.
"A delegate may sometimes believe police have over-reacted, but those on the other side could say the visiting fans did the same."