Liverpool defender Mamadou Sakho is set to respond to UEFA's investigation into his failed drugs test on Tuesday.
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 Tuesday.
Former Liverpool defender Jamie Carragher has hit out at Sakho, saying the 26-year-old has "let himself and his club down badly''.
Carragher told Sky Sports: "It's a nightmare for the player.
"I think he's let himself and his club down badly, because he was becoming a really important player for Liverpool.
"There are serious questions to be asked of him.
"He's had a great campaign. He's one of the leaders of the team now. You think of the Borussia Dortmund game, the Manchester United games especially, how well he played in those. It's now how Liverpool fill that void.
"But for a professional footballer - or any sportsman, really - it's not acceptable.''
The British Dietetic Association (BDA) says the Sakho case should warn players there is no ''magic answer'' to solving weight issues.
''The culture has moved away from food and towards supplements and using potions and lotions,'' BDA spokesperson Aisling Pigott told Press Association Sport.
''But athletes have to be extremely careful because unless those supplements are legal there is a big risk that they could be contaminated.
''Fat-burning supplements are difficult to monitor and if there was anything reliable to burn fat, it would be introduced across the board in the health service because of the (obesity) crisis we have.
''People are looking for the magic answer all the time, but it does not exist.''
Pigott added: ''It's also vital that any organisation knows the risk of supplements, and football clubs must spend more time on education and have a broader level of knowledge.
''They must make it clear that it's not a good idea for a player to go into a shop and buy a fat-burning supplement, because it just doesn't work.''
Source: PA
