Liverpool midfielder Mohamed Sissoko is set to be out of action for three months after dislocating his shoulder.
The all-action midfielder sustained the injury in the first half of Liverpool's 1-0 win over Birmingham in their Carling Cup tie on Wednesday.
Sissoko was stretchered off the field and had to spend the night in a Birmingham hospital.
Scans have shown that Sissoko will have to undergo surgery to correct the problem and he is expected to be sidelined for three months.
"Unfortunately Momo will require surgery which is scheduled to take place next week," said a Liverpool spokesman.
"It is anticipated he will be out of action for three months."
The news is a massive blow for Liverpool as they look to get stuttering Premiership campaign back on track.
The former Valencia man is unlikely to pull on a Liverpool shirt again until February at the earliest and it means Steven Gerrard is likely to revert to his preferred central midfield role in place of Sissoko
Liverpool team-mate Xabi Alonso admitted it was a blow to lose Sissoko, but he is confident that his partnership with Gerrard can help fill the void left by Sissoko's enforced lay-off."If he's out, it's clear we'll have to change something in the team," said Alonso. "There are times when we've played without him before and we've still managed to get good results.
"But now we will have to think of a new system and I'm sure Rafa will do something.
"Stevie and I have played together in the middle a lot. Sometimes it's worked really well and other times we've had some problems.
"We know we need to work together to find the balance which is important for the team.
"Stevie has massive qualities. He has an ability to get into the box and we have to make sure he's still able to do that because that's where he works so well.
"If the team is compact and we work as hard and show the same form we did last season, I'm sure the identity of the players in the position isn't important. It will be harder without Momo, but we can make it work."