UEFA started an investigation over racist abuse directed at Liverpool's Djibril Cisse during a Champions League match in Bulgaria.
Europe's governing body will also examine whether fans set off fireworks in the same match.
The case was opened after UEFA received the official delegate's report from CSKA Sofia's match against Liverpool earlier this week. UEFA's control and disciplinary body will consider the case at its next scheduled meeting on Aug. 18.
Defending champion Liverpool won the third-round, first-leg qualifying match 3-1 in Sofia, Bulgaria, on Wednesday night.
Cisse, a French international who is black, scored one of the goals and was the subject of monkey noises from sections of the crowd.
"It is hurtful when it happens," Cisse told the Liverpool Echo on Thursday. "It began when I tried to cross the ball they started to do all these monkey noises.
"You can say UEFA should take stronger action when it happens but I'm not sure what they can do about it. You can't really stop these kind of people doing this."
Cisse said it was the first time he had been racially taunted while playing soccer, the AP reports.
Photos show many anti-Ukrainian and anti-EU slogans that the farmers use in their demonstration. One of the banners attached to a tractor calls on Russian President Vladimir Putin to bring "Ukraine, Brussels and our rulers” to order