Manchester United managed to earn a point from their visit to Anfield last Sunday, adopting a cautious approach and limiting Liverpool to little in the way of opportunities.
Liverpool will be the visitors this afternoon as Manchester United will be hosting them at Old Trafford in the fourth round of the FA Cup.
Mellor stressed that Manchester United were more defensively organised and cautious while not committing many of their forwards at Anfield last weekend.
But he is expecting their approach to be different now as they will be playing at home and the former Red is hopeful that Liverpool will be more clinical in front of goal this time around.
The former Liverpool star said on LFC TV: “Manchester United were really cautious in their approach, we have to say that.
“The way that they defended and were organised. They didn’t commit too many [of their] players forward.
“Until the closing stages, Manchester United were really compact defensively and I think it will be a different performance from United when they will be at home as opposed to being at Anfield.
“Against Manchester United, this time around, we need to be a bit more clinical and force the goalkeeper into doing a little bit more than certainly we did at Anfield.”
Liverpool are in the middle of a poor run of form where they have failed to score in any of their last four league games.