Both Manchester United and Chelsea will be licking their wounds after European defeats in midweek, and each will now be even more set on achieving FA Cup glory this season as they prepare to face off at Old Trafford.
Here is a run-down of the key battles...
Wayne Rooney vs David Luiz
It what must have been one of his more bizarre weeks at Manchester United, Wayne Rooney has faced a barrage of speculation over his future at the club after not being included in the starting eleven for their match with Real Madrid. Alex Ferguson has said that Rooney will be there next season, and the player will be desperate to make a point against Chelsea this weekend. Rooney has a good record against Chelsea, and Luiz will be keen to stop him from making a statement about his place at United by running the show against the Blues.
Tom Cleverley vs Juan Mata
Mata didn't start Chelsea's match with Steaua in midweek as Rafa Benitez sought to rest his star player ahead of the match with United. However as the Blues struggled Mata was forced to come on, and this again demonstrated their reliance on the brilliant Spaniard. Mata's form has dipped slightly of late as he has been rotated in and out of the side, but he is still the key to Chelsea's attack, and Cleverley will need to help out his defence to combat Mata's incisive play in the final third.
Shinji Kagawa vs Joh Obi Mikel
A hat trick against Norwich wasn't enough to earn Kagawa a starting place against Real Madrid, but it is likely he will return to the attack for Chelsea's visit this weekend. The Japanese player is starting to show the talent that made him such a force for Dortmund, and Mikel will have to ensure he isn't allowed space in and around the box, as Kagawa has proven himself a composed finisher when given the opportunity.
Rafael vs Eden Hazard
Manchester United were reportedly one of the sides that Eden Hazard turned down to join Chelsea during his protracted transfer saga last summer, and whilst he has had a mixed first season in England, there's no doubt he can be lethal on his day. Rafael has come on hugely this season at United, but he will face another examination of his defensive ability this weekend with Chelsea's fluid attack likely to pose plenty of challenges. Rafael can also be important going forward, as if Hazard neglects his defensive duties, the Brazilian full back could help overload Ashley Cole at left back.
Robin van Persie vs Gary Cahill
The Dutch striker is going through his first dip in form at Manchester United, and he will know that if he had been a bit more clinical over two legs against Real Madrid, United would likely have gone through. Van Persie will be hoping to move past that this weekend, and Cahill will have to monitor him carefully to stop him getting the half yard of space in the box that is all he usually requires to find the net.
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