Reds boss Rafael Benitez admitted it was a blow to lose his skipper.

"I'm disappointed because Gerrard will have an operation tomorrow," he told the club's official web site.

"He has a groin problem. We knew it could be like this and I was surprised when I was reading some of the newspapers saying he has to play and has to start but he had a problem and now he will have an operation and will be out for 10-15 days.

"It isn't too much because he needs to have it because he is having pain with it. When he went with the national team we knew he had a problem and in the first-leg too.

"I was talking with the doctor yesterday and today we talked with him. He said he would play with pain and after it he would have an operation.

"He knew he had to keep going tonight because he was having the operation tomorrow."