UEFA has provisionally suspended Mamadou Sakho for 30 days after he failed a drugs test following Liverpool's Europa League clash with Manchester United last month.
A UEFA statement read: "Disciplinary proceedings have been instigated against Liverpool FC player Mamadou Sakho, following the UEFA Europa League round of 16 second-leg match between Manchester United FC and Liverpool FC (1-1), played on 17 March.
"The proceedings relate to a violation of the UEFA Anti-Doping Regulations, after the player failed a doping test at the above-mentioned match.
"The player did not request the analysis of the B sample. UEFA has now suspended the player provisionally for 30 days until a final decision is taken by the UEFA Control, Ethics and Disciplinary Body.
"The date of the disciplinary hearing will be announced at a later stage."