Liverpool boss Roy Hodgson fears Dirk Kuyt's recent injury could rule the striker out for more than the predicted four weeks.

The Dutchman recently ruptured ligaments in his shoulder when attempting a bicycle kick in training while on duty for Holland.

The 30-year-old is hoping to return in time for the Reds' UEFA Europa League trip to his former club Utrecht at the end of September, but Hodgson believes he could be sidelined for longer.

"It could be more than four weeks. It's one of those injuries where it's very difficult for the doctor to say and I think four weeks is a very conservative estimate," Hodgson told the club's official website.

"If we're lucky, it could be earlier, but it could be longer. We have to be very careful because it's the type of injury that has to be treated with a lot of respect.

"It's a great blow for us because Dirk is an important member of our first team. He does a job which is not easy to replace because he has all the qualities required for that role on the field.

"I was very sad to see such a thing happen, especially in a training session.

"He's a quick mender and he has a great mentality and attitude towards recovery, so he will be back as quick as is humanly possible."

Kuyt's injury caused some worry in terms of Liverpool's attacking force, with David Ngog already struggling with a hamstring problem.

The 21-year-old was withdrawn from France Under-21s duty, but Hodgson is hoping he will be available for Sunday's clash at Birmingham.

"He has been nursing a problem but is much better now," he said.

"I am hoping that he will recover in time for this weekend. We have nursed him through and hopefully he will train either today or Friday."

Fabio Aurelio, though, is still ruled out with an Achilles problem.

Hodgson added: "Fabio is making very good progress and is definitely moving in the right direction. It was a relatively minor problem but one we had to nip in the bud because Achilles injuries can be very problematic."