Liverpool captain Steven Gerrard has undergone surgery on the groin injury that has curtailed his season.
The 30-year-old was told he needed the procedure after suffering a setback in his recovery from the problem that has kept him out since early March.
A statement said: "Liverpool FC confirm that Steven Gerrard has undergone successful surgery on his groin."
The club added that the England midfielder is now "expected to return for pre-season training."
Gerrard has spent the week undergoing assessment at the club's Melwood training ground where Reds manager Kenny Dalglish confirmed on Friday he was due for the operation.
The statement added: "The decision was taken after consultation with leading specialists."
He last played for Liverpool on 6 March during the 3-1 victory over Manchester United in the Premier League and was expected to return for last Saturday's 2-1 defeat at West Brom.
The news of Gerrard's absence adds to Dalglish's worries after defenders Daniel Agger and Glen Johnson were injured at The Hawthorns last weekend.
Centre-back Agger picked up a knee problem that has ended his season while Johnson injured his hamstring, sidelining the right-back out for at least a month.
Liverpool face Manchester City on Monday in their chase for a Europa League spot. Even though they are sixth in the Premier League, they are five points behind fifth-place Tottenham, who have a game in hand on the Merseysiders.
Dalglish added: "It is a blow to anyone but it's more disappointing for the player than it is for us, obviously.
"We just have to get on with it and without being disrespectful to the players who are injured the most important ones are the ones who are fit.
"They are the ones who can be chosen. At this particular moment in time I'm as good a player as Steven."