We have a genuine chance for a TREBLE (not including the Europa), so Sunday is 100% VITAL for our progression - irrespective of whether we are playing the rags or not.
I have been saying that for me, progress this season would be 1st or 2nd in Premiership & another Cup of some kind. Just because we are in the semi-final of the League cup, does not lessen the importance of the FA Cup. There is no way that Fergie will put out a crap team for Sunday (when we met the rags in the semi of the league cup last time, he finally took it seriously) and we have a strong enough squad to put out a serious team against them.
Mancini will also want to win on Sunday - without doubt. He will want all options open going into February and by then, we will know if we are in the final of the League Cup and then, if he is going to take anything less seriously, it will be the Europa.
I am perhaps slightly biased coz I have a couple of riding bets on getting a treble this season at around 80/1 each