Manchester United assistant Carlos Queiroz believes Liverpool are genuine title challengers ahead of Sunday's Anfield showdown.
The two historic rivals are poised to go head-to-head for the first time this season and Sir Alex Ferguson's number two has warned the United players to expect a thorough examination of their own title credentials.
The Portuguese coach has also singled out £20million summer signing Fernando Torres for special praise.
The Spain international striker has already scored 12 times in all competitions this season despite picking up several niggling injuries.
"I have been in England for five years and I have never seen a Liverpool side looking so strong in the league at this point of the season," said Queiroz.
"Torres is doing really well and I am impressed with him. He is already going some way to making the difference for Liverpool this season.
"I think he's a good finisher and he's a player who gives Liverpool something completely different.
"Certainly we will have to be careful of him because he is dangerous. We are always confident in what we can do and we will not worry too much. But we do recognise his quality."