Liverpool will be without first-choice centre back Joel Matip when they visit Brighton and Hove Albion in the Premier League on Saturday, their manager Jurgen Klopp said.
Matip returned to the side for last Saturday's 1-1 draw at Chelsea after missing the two previous games with a thigh strain, but picked up a muscular injury in Liverpool's 3-0 win at Stoke City in midweek.
"It looks like Joel Matip is out," Klopp told a news conference on Friday. "After the game he had a problem, he felt something muscle-wise, we have to make a final assessment but it doesn't look like he's available for tomorrow."
Matip's unavailability could leave fifth-placed Liverpool short of cover in central defence as second-choice Ragnar Klavan has been ill, and raises the possibility of Klopp moving Joe Gomez into the centre for the first time this season.
Gomez put in an impressive display at centre back for England against Brazil in a friendly last month, but has been deployed exclusively at right back by Liverpool so far this season.
"Ragnar Klavan was ill, hopefully he isn't any more especially when you think about Joel Matip's situation. So it's not that we have a big choice to make in defence," Klopp said.
Liverpool head to 10th-placed Brighton having won four of their last five league games. However, the promoted side are enjoying life in the top-flight and have not lost at home since a 2-0 opening day defeat by league leaders Manchester City.
"It's a really strong group of good players, good new signings," Klopp said. "Together with the manager obviously it fits really well together. They are not a counter-attacking side or a long-ball side only, but they have all this stuff.
"They have unbelievable quick wingers for the counter-attacks, yes they defend deep and together, they play long balls, but they play football as well because they have the skill players for that, so it's a mix-up.
"It was very interesting to analyse to be honest... So we should expect it will not be easy for us. We are in a good moment as well so we should use that. That's the target for the game."