Liverpool were booed off the pitch by their supporters on Saturday, after a poor 0-0 draw with newly promoted Birmingham raised fresh doubts as to whether the manager can deliver the title to Anfield.

Having won three of their first four games to go top of the Premier League, Liverpool have now failed to win - or score - in their last two domestic matches.

Benitez faced fresh questions about his controversial rotation policy as Spanish striker Torres was kept on the bench for an hour before being sent on.

The manager had opted to use Dirk Kuyt and Andriy Voronin before sending on Torres, who went close to sealing the points in the closing stages with a spectacular overhead kick.

Benitez said: 'I have four strikers and I need to use two of them. We knew Birmingham would play deep and I took the decision to play Voronin and Kuyt.

'Of course it's frustrating that we haven't won, but Birmingham worked hard and defended well.'

Birmingham boss Steve Bruce gave a diplomatic response when asked whether he would have kept Torres on the bench if he had such a striker.

The former Manchester United defender said: 'Who am I to argue with Rafa Benitez after all that he has achieved?'

Benitez admitted his side ran out of ideas towards the end of a dreadful game in which Jermaine Pennant injured a hamstring.

According to the manager, the injury is not serious, although Pennant is unlikely to be risked tomorrow when Liverpool face Reading away in the third round of the League Cup.

He added: 'We didn't have space or any clear ideas at the end. In this kind of game, you must win the second ball.

'We had some chances, but we couldn't score. Am I worried about us not scoring? Yes. But we could have scored very early on and then it would have been different.

'But you have to take your chances. I'm frustrated, but we must keep going.'

Birmingham are fast becoming Liverpool's bogey team after emerging undefeated for the third successive time at Anfield.

AGENCE FRANCE-PRESSE