Liverpool manager Brendan Rodgers says defender Jose Enrique will miss Saturday's derby against Everton with a knee injury which will require surgery.
The Spaniard, 27, only returned from injury in the 4-0 win over Fulham on 9 November after a month out.
"It looks like he'll probably need a small operation," Rodgers told Liverpool's website.
"It's disappointing because he's been out for two months. We've tried ways to get him back, he's still in pain."
Enrique, a £6m signing from Newcastle in August 2011, has started six Premier League games this season.
Liverpool are second in the Premier League table ahead of their first Merseyside derby of the season, at Goodison Park.
Meanwhile, the Reds have sacked Academy director Frank McParland and the club's head of coaching Rodolfo Borrell.
Liverpool have refused to comment but BBC Sport understands the move is down to the club wanting a change of direction.
McParland and Borrell represented the last of former Reds manager Rafael Benitez's backroom staff at Anfield.