Eden Hazard v Ander Herrera
Herrera did a superb man-marking job on Hazard when Chelsea lost at Old Trafford 13 months ago. He may be tasked with repeating it, and avoiding the red card he collected for fouling Hazard in last season's FA Cup. Conte's 3-5-1-1 formation puts more emphasis on the Belgian to create. If Herrera can stop him then Chelsea could be stopped.
N'Golo Kante v Paul Pogba
France team-mates with different attributes. Pogba was a player Chelsea wanted in 2015. Instead he became United's record signing 12 months later. Criticism is that he has not decided enough major matches, but he scored twice in last month's Manchester derby. Yet Kante is unlikely to allow him such freedom to dominate.
Cesar Azpilicueta v Alexis Sanchez
Sanchez is an FA Cup final specialist, a scorer in the 2015 showpiece and Man of the Match for Arsenal against Chelsea 12 months ago, when he got the opening goal. Azpilicueta will have to track him, but Chelsea's most consistent defender also set up their November winner against United, with a cross that Alvaro Morata headed in.