Liverpool's title aspirations were hit by a severe blow after it was revealed that striker Fernando Torres is out for a longer period than first thought due to a damaged hamstring.

The 24-year-old Spanish forward, who suffered the injury during the Champions League win over Marseille last month, had been expected to be out of action for two weeks but has now been told by specialists that he will be out for at least four weeks.

"We first said two to three weeks but do not want to put a time on it now," said Liverpool manager Rafael Benitez.

"He will come back when he is ready. We will not rush him back.

"We want to resolve this problem once and for all and we will make sure we do that."

Torres has been plagued by hamstring problems over the past 18 months, suffering the injury five times in that period.

Liverpool are currently analysing his training schedule with both club and country in an attempt to resolve the problem.

Benitez had questioned the Spain training regime and believes it could be the cause of his injury.

"He has been injured now three times while with the national team and it is something we have to analyse," he stated.