Mellor, who netted his first ever senior goal for the Reds against the Blades in that League Cup semi-final during the 2002/03 season at Bramall Lane has made 15 appearances (+ 7 as sub) whilst netting six goals. 
The Manchester born striker has found life tough at Anfield since the signature of Fernando Morientes (Real Madrid) and Peter Crouch (Southampton) whilst Rafa Benitez already has six strikers to choose from there is the treat that Michael Owen could return to his former club.
With this Blades boss Neil Warnock has stepped up a gear since losing out on the signatures of Heidar Helguson and Richard Cresswell and will now try and land Mellor before the transfer window closes at the end of August.
Warnock told sufc.co.uk "We have tabled a bid of around as we need a striker of his caliber. He has good movement, an eye for a goal, and is very athletic. He's from Sheffield, and we think he would do an excellent job for the Blades.
"Other clubs are interested, and it remains to be seen whether Liverpool would be prepared to sell Neil to anyone at this time, or whether they would prefer to wait until the January transfer window. We'll have to wait and see.
"I've made bids for three strikers, all different types of player, but all of real quality. It's a question of seeing which of them becomes available. If one does, I'd have to take a chance on him without knowing how the other two situations might unfold."