Manchester United boss Sir Alex Ferguson won't write off Chelsea striker Fernando Torres.

Ferguson is wary of the potential threat from Torres, especially if he returns to the goal-scoring form he was in against United when he wore a Liverpool shirt.

"He did well against us then,' he said.

"I don't know the whole situation at Chelsea and I don't know the boy. 'I don't know what makes him tick, but I know at Liverpool he was a threat to us - no doubt about that."