UEFA could act after a section of Real Madrid supporters aimed racist abuse at Bayer Leverkusen players.
A week after the Bernabeu was witness to appalling crowd behaviour during England's international friendly against Spain, when Shaun Wright-Phillips and Ashley Cole were subjected to monkey chants from the home fans, there was more cause for concern for the Spanish authorities.
European football's governing body may see fit to intervene, should the referee or their delegate report last night's events.
Several members of the Bernabeu crowd could be seen making Nazi salutes, and Leverkusen's black defender Roque Junior - a World Cup winner with Brazil two years ago - was singled out for abuse from the stands.
UEFA were powerless to act after similar scenes in last week's international, which fell under FIFA control.
