Jurgen Klopp has offered a negative prognosis of the injury sustained by Adam Lallana in Liverpool's 2-1 win at Crystal Palace.
The midfielder came off the bench in the 65th minute but played only five minutes before falling heavily under an innocuous-looking challenge.
Lallana, who replaced Georginio Wijnaldum, ended up limping off the Selhurst Park pitch as Dejan Lovren took to the field in his place.
"It is not good, he is really down in the dressing room," Klopp told BBC Sport after Saturday's victory.
"He's our boy, our best friend. It is really difficult, whatever injury it looks like a muscle one."
Lallana has experienced thigh trouble this season, which has caused him to sit out the majority of the campaign.
