Sakho sat out Saturday's 2-2 draw with Newcastle with it having emerged shortly beforehand that UEFA was investigating an alleged anti-doping violation - understood to be associated with a 'fat-burning' supplement - following the Europa League tie at Manchester United last month.
The France international, who has not been suspended either by Liverpool or UEFA, faces an anxious wait to see whether he will receive a playing ban.
He is likely to ask for his B sample to be tested, with the deadline for that request set for today.
Source: PA