Liverpool's preparations for this weekend's Merseyside derby have suffered a blow with defender Jose Enrique ruled out with a long-term knee injury.
The Spanish left-back has been struggling with the problem for much of the season and manager Brendan Rodgers confirmed the former Newcastle player would probably require surgery.
"We're just waiting for clarification on his injury, but it looks like he'll probably need a small operation," Rodgers told reporters at Melwood.
"It's disappointing because he has been out for a couple of months and we've tried various ways to get him back fit. But he's still in pain.
"The conclusion will be that he'll need the operation and we'll assess it from there. I just need to wait and see, wait to hear from our head doctor later on (Thursday), and we'll get a better idea of how long that will be."
Summer loan signing Aly Cissokho has deputised in defence but with youngster Jack Robinson on a season-long loan at Blackpool, Liverpool are now short of cover on the left.
Rodgers also admitted England forward Daniel Sturridge, who completed 90 minutes in the 1-0 friendly defeat by Germany at Wembley, would have to be monitored ahead of the showdown at Everton.
The Reds boss said: "He obviously went to England with an injury. He's had a dead leg for about three to four weeks that he has been playing through. He hardly trained when he left, after the Fulham game.
"We'll assess him; he's back recovering after that, with the other international players. We'll see how it is over the next couple of days."
But summer signing Kolo Toure, who missed Liverpool's last encounter - a 4-0 victory at home to Fulham - is back in contention for Saturday's short trip to Goodison Park.
Meanwhile, Sky sources understand that the club's head of coaching Rodolfo Borrell and academy director Frank McParland have both left their posts.
Borrell was brought to the club by former manager Rafa Benitez in 2009, having previously spent 13 years working with Barcelona where he helped develop the likes of Lionel Messi, Gerard Pique and Cesc Fabregas.
McParland also joined the club in 2009 and has overseen the development of Andre Wisdom, Raheem Sterling and Martin Kelly, all of whom have broken into the first team set-up at Anfield.