Supporters were clearly heard chanting “Anton Ferdinand, you know what you are” in their 1-1 draw at the Cristal Arena.
Chelsea’s fans appeared to be attempting to show support for captain John Terry, who is now under police investigation over allegations he racially abused QPR defender Ferdinand during last month’s west London derby, something he denies.
Chelsea look set to avoid action over the abuse levelled at Ferdinand by a section of their travelling support, with UEFA confirming that neither their match delegate nor referee Svein Oddvar Moen made any mention of the chanting in their reports.
But the club took the initiative themselves yesterday afternoon in a bid to prevent a repeat.
A spokesman said: “The chanting last night by a vocal minority was wholly inappropriate and Chelsea Football Club does not condone such behaviour.
“We will be working with the appropriate authorities to seek out those responsible.
“Last night’s offensive chants were from a minority and, as such, they do not represent what supporting Chelsea Football Club is all about.”