There will be quite a few anxious faces as Manchester United host Chelsea in the second leg of the Champions League quarterfinals, with an aggregate lead of 1-0 over their London rivals.

Chelsea find themselves fighting history as only two teams in the Champions League's past have managed to overturn first leg deficit's to progress - Ajax beat Panathanaikos  3-0 in the second leg in 1996, while earlier in this year's tournament Inter beat Bayern Munich to progress to the quarters.

Failure to progress could almost certainly see manager Carlo Ancelotti axed either immediately, or at the end of the season, despite Ancelotti stating in the weekend that his future was decided. Progress, though, could mean a seemingly manageable clash against Schalke (as the German side thrashed Inter 5-2 at the San Siro in the first leg) in the semis.

A big question that surfaces before every game Chelsea plays these days is whether Fernando Torres will feature, and more importantly, score. It is unclear how Ancelotti will set out his team today. He started with his old guard of Anelka and Drogba up front in the 1-0 win over Wigan at the weekend. It could either mean Torres was rested, or that Ancelotti would go with the tried and tested Drog-Anelka combination.

Quite simply, the result of this game could make or break Chelsea's season and could see a major upheaval in the summer.

It will come as a surprise to some that Manchester United are in contention for the treble this season. For others, it would seem natural. United haven't had the best of seasons. They haven't been playing as fluently and clinically as they have in the past, but they have been grinding out results.

Rio Ferdinand, who made a surprise recovery in time to face Chelsea last week, has dispelled claims that the prospect of a treble could distract United. He said, The treble is not a motivation. Our motivation is each competition. If that amounts to winning the Double, a single trophy each year or the Treble so be it. I don't think the players who won the Treble were saying 'this is it, we want to win the treble'.

It is about making sure this club wins a trophy every year. If you win one and you see another one, you want to try and win that.''

Wayne Rooney scored the solitary goal at the Bridge last week to hand United a vital away win, also a first win at the Bridge in nine years, and it could prove decisive unless Chelsea turn up in full force today. Since Chelsea will have to go forward in search of a goal, it could leave them vulnerable at the back to United's incisive counter attacks. Add that to the huge atmosphere at Old Trafford, and Chelsea really do have a mountain to climb. United will be looking to attack Chelsea on the counter, and the pace of Hernandez and Rooney up front could prove a David Luiz-less Chelsea defence some trouble.

If Chelsea manage to score early though, it'll change everything and could pan out to be an open, end-to-end premiership encounter in Europe.  The minimum Chelsea will be hoping for is a 2-1 win, which will send them through on away goals. However, they will take a 2-0 to be on the safe side. If at the end of 90 minutes the score stays 1-0 to Chelsea, then there will be extra time and penalties. And we all know what happened the last time the two sides decided a tie in penalties!

Team News -

Manchester United's only injury concern is Brazilian full back Rafael, and the times when United had a defensive crisis seems eons away.

Chelsea has a fully-fit squad, for the first time this season, after recent recoveries from Alex and Benayoun. However, David Luiz is cup-tied and is unavailable.

Match Fact -

Wayne Rooney has scored seven goals in his last seven games against London teams in all competitions this season, but Manchester United have scored just ten goals in nine Champions League games this term. Torres has failed to score in 648 minutes for Chelsea, having 28 shots of which 12 were on target. (Source - ESPNSoccernet)

Prediction -

With a 1-0 advantage and the backing of Old Trafford, Manchester United are favorites. And though a Chelsea goal could change it all, a 2-1 win for United seems probable.