Liverpool midfielder Lucas Leiva has successfully undergone surgery on his Anterior Cruciate Ligament injury, according to a club statement.
The Brazilian sustained the injury during The Reds' Carling Cup victory over Chelsea at Stamford Bridge, ruling him out for the remainder of the season.
After having an operation on the injury back in his homeland, Liverpool have confirmed it was a success.
A statement read: "Liverpool confirmed this afternoon that Lucas had successfully undergone surgery in Brazil on the Anterior Cruciate Ligament injury he sustained at Chelsea last week.
"LFC medical staff were present during the procedure.
"Lucas will now begin an agreed rehabilitation programme which will be overseen by the Club's medical team."
The loss of Lucas is big blow to Liverpool's hopes of qualifying for the Champions League, and it is as yet unknown if the club will delve into the transfer market to purchase a temporary replacement for the 24-year-old.
The injury leaves the club short in midfield, and following the dismissal of Jay Spearing against Fulham, which the club have chosen not to appeal against, Liverpool may have to call on Jordan Henderson, who has often occupied a right-hand side birth this season, or the recalled Jonjo Shelvy to fill in during the festive period.
Shelvy netted six goals in 10 games on loan at Blackpool this season, but saw his short-term deal cut short at Bloomfield Road following the injury to Lucas.