Liverpool manager Jurgen Klopp has admitted that he is unsure over the severity of Alberto Moreno's injury after the defender left the field in tears during last night's 7-0 thumping of Spartak Moscow at Anfield.
The Reds sealed qualification to the last-16 stage of the Champions League in fine style but were dealt a potential blow when the Spanish left-back was forced off in the first half following a collision with Spartak's Roman Zobnin.
Moreno has been a key component of Klopp's Premier League plans this term, featuring 12 times, but is now a doubt for this weekend's Merseyside derby with Everton.
"That was the shadow of the night. It was a strange situation," Klopp told reporters after the game. "He's a tough guy.
"If he can't continue the game you should consider if it is something serious but in treatment room he was a little bit more positive. Maybe are lucky and it's not too serious, we'll see.
"We need all the boys for the next few weeks but especially for the game on Sunday."
The Reds will go into Sunday's game 11 points clear of their Merseyside rivals in the Premier League table.
