Joel Matip has become the second Liverpool defender to be ruled out for six weeks.
Matip recently returned into the Reds’ centre-back pairing alongside Virgil van Dijk after Joe Gomez was sidelined by an injury picked up against Burnley.
Now the Cameroon international finds himself out of action with a broken collarbone sustained late in Tuesday’s Champions League win over Napoli.
“Joel Matip is set to undergo surgery after suffering a fractured collarbone during Liverpool’s 1-0 win over Napoli on Tuesday night,” read a club statement.
“The defender landed awkwardly following an aerial challenge in the closing seconds of the game, in which the Reds secured a place in the last 16 of the Champions League.
“Matip was taken to hospital following the fixture and further assessment deemed an operation is required.
“Early indications suggest the centre-back is facing a spell of of up to six weeks out of action, though that is dependent on how Matip responds to his treatment and rehabilitation programmes.”
It means that Liverpool will have Van Dijk and Dejan Lovren as their only established central defenders heading into the midst of the Christmas period.
Sunday’s visit of Manchester United is followed by clashes with Arsenal and the Anfield club’s Premier League title rivals Manchester City in the coming weeks.
Jurgen Klopp also faces an anxious wait on the fitness of Trent Alexander-Arnold after the 20-year-old limped off in the final stages of the Napoli victory.