UEFA is waiting to receive a report from the English Football Association into alleged anti-Semitic chants directed by Lazio fans at Tottenham during a Europa League match.
The English FA says its crowd control adviser who attended Thursday's game "will provide an urgent report" to UEFA into incidents at the Olympic Stadium in Rome.
UEFA says it is awaiting reports from the FA and its own match delegate, Teuvo Holopainen of Finland.
The match was played amid tension following violent attacks on Tottenham fans in a Rome city center bar late Wednesday.
UEFA fined Lazio €40,000 ($51,600) for its fans' racist behavior when the teams played in London in September.