Chelsea can take another stride towards the Premier League title on Sunday with victory at Old Trafford, but in Manchester United manager Jose Mourinho, they face a man who knows them better than most.
Having thumbed United 4-0 in the league in October, Chelsea knocked Mourinho’s men out of the FA Cup with a 1-0 victory in March.
It will be the third time the Blues have faced their former boss since his sacking in December 2015, their first time at Old Trafford, and Mourinho is well aware of the threats Chelsea pose.
"They have a certain style of play. They stick to it, they do it very well.
"Not every team defends with 11 players and they defend with 11 players. Not every team is so objective in their counter-attacks.
"They are very objective in the counter-attack and they have individual players out of the context of the game that can also resolve the problems, so they are a very strong team."
When the sides take to the field on Sunday it will have been eight days since their last match, while Manchester United had their Europa League encounter in Anderlecht on Thursday night.
Mourinho knows freshness could prove a decisive factor.
"First of all, some guys are fresh, some guys are tired," said Mourinho. "That's very important in football.
“But for some reason they are top of the league, it's not just because they are fresh. It's also because they have individual quality and they have collective quality.”