Uefa is investigating an alleged case of racist abuse towards Callum Hudson-Odoi during Chelsea’s Europa League win at Dynamo Kiev on 14 March.
Chelsea complained to Uefa after winger Hudson-Odoi, 18, was subjected to monkey chants from some Kiev fans.
Skipper Cesar Azpilicueta told the referee while Blues chairman Bruce Buck also spoke to the Uefa delegate.
If European football’s governing body finds “sufficient evidence” it will “open disciplinary proceedings”.
If Uefa finds a club guilty of racism, it can be punished with “a minimum of a partial stadium closure”.
A second offence is punished with one match played behind closed doors and a fine of 50,000 euros (£42,500).