I'll forgive you for thinking that the headline to this article is obvious. Liverpool need one of their three world-class players to be at their best against one of their biggest rivals? Well that's hardly shocking.
But this is a massive game for Fernando Torres. The Spanish striker has struggled so far this season and hasn't shaken off the slump in form that plagued him during this summer's World Cup.
Things were looking up after Torres scored in Liverpool's 1-0 win over West Brom and then bagged two in Spain's win over Liechtenstein.
Then came the goalless draw against Birmingham last weekend. In truth, few players—with the notable exception of Pepe Reina—came out of that game with much credit, but Torres drew more criticism than most for his display.
Particularly vocal was former Liverpool player and current pundit Jamie Redknapp. The former England international let his feelings be known to all both during the game in his role on Sky Sports, and then in his Daily Mail column the next day.
The words used by Redknapp were "sloppy and lethargic." More than just saying Torres was lacking form or fitness, Redknapp was questioning the striker's commitment to the cause.
Speaking at halftime, he described the striker's performance as "diabolical," saying that he wasn't chasing balls, had lacked appetite for the game, and basically just wasn't up for the fight against two very physical Birmingham centre-backs.
I actually have a lot of time for Jamie Redknapp, partly because he was one of my favourite players growing up, but also because I think as a pundit he is generally fair and reflective (unless he's talking about one of his dad's teams).
I watched that Birmingham game and yes, if it wasn't for Reina, Liverpool would have lost that match and comfortably so. But was Torres the worst player on the pitch? No. Did he miss chance after chance? No.
I'm not saying that Torres had the game of his life, because it's clear for all to see that he's struggling for form and for that extra yard of pace that makes him so dangerous in and around the penalty box.
What I want to argue is that Torres is a striker, playing in a system that has him playing up front on his own. This leaves him prone to being isolated—something that was particularly true against Birmingham.
The other major consideration is that Torres needs decent service from his teammates. Everyone knows that Torres' main strength is his pace and, where possible, balls up to him need to feed that strength.
Against Birmingham, you would have thought he was a six foot-plus target man. I lost count of the number of balls that were just played aimlessly in the generally direction of Torres, and not even along the floor.
Against Richard Johnson and Scott Dann, Torres had no chance of coming out on top with service like that.
They weren't even balls that were being played into the channels or over the heads of full-backs for Torres to chase. They were straight at the heads of two Birmingham centre-backs for whom dealing with balls like that is their bread and butter.
And so here come Manchester United.
Torres has a good record against United and has scored in each of the last three meetings between the two teams.
Moreover, he has had the better of Nemanja Vidic in these contests and the Serbian defender has shown uncharacteristic nerves when up against the Spaniard.
A big plus for Torres will be the return of Joe Cole after the latter's suspension. If manager Roy Hodgson chooses to play Cole behind Torres—as I hope he does—this then allows Steven Gerrard to drop deeper and have more influence on the game.
The combination of Cole and Gerrard should ensure that Torres gets decent service and if this happens, then the Spaniard could have a good day.
I've always felt that Torres quickly understood the psychology of the club after joining from Atletico Madrid and he's said the right things this week.
Speaking about the United game, he was quoted in the Guardian as saying, "It means everything to them[the Liverpool fans]."
"We are the two most successful teams in England but it has not been nice for the Liverpool fans to watch Manchester United have so much success over the recent years. We have a great squad and a great manager, and we really hope to give the fans a trophy this season, as well as beating Manchester United for them."
I don't agree with him that Liverpool have a great squad, but the sentiment is right.
Every game against Man United is a big game for both clubs, but there is an extra sense of importance surrounding this one.
With one win from four Premier League matches, Liverpool are looking to ignite their campaign and there would be no better way of doing it than coming away from Old Trafford with three points.
If this is to happen, then Fernando Torres needs the service from his teammates that allows him to do what he does best.