Liverpool will be without captain Jordan Henderson for an extended period of time after the midfielder underwent an operation.
The club confirmed on Friday morning that the England international went under the knife on the injury he sustained during last weekend's Merseyside derby with Everton.
Henderson was withdrawn after half an hour of the Anfield fixture with what seemed to be a groin issue.
"Liverpool can confirm Jordan Henderson has undergone an operation on the injury he sustained during last weekend's Merseyside derby with Everton," read part of the statement.
Adding; "Following further assessment with the club’s medical team, Henderson has successfully had a corrective procedure carried out on the adductor injury. He will begin a rehabilitation programme immediately.
No specific timescale though has been placed upon his return but should be back after between four to five weeks.
His injury comes at a time when the club is going through a rough patch, losing four consecutive home matches and dropping out of the Premier League race.
The Reds remain sixth on the standings, 19 points off league leaders Manchester City, and five points off West Ham, who hold the last Champions League qualification spot.