#2 Manchester United
Manchester United's poor start to the season has been in large part due to a rigid and static midfield.
Paul Pogba has been one of their few good performers in midfield so far, in spite of his inconsistencies.
Nemanja Matic has become very slow despite his impressive form last season, and his mistake led to Newcastle's second goal on Saturday. Marouane Fellaini has improved, but still remains more of an impact substitute.
Ander Herrera is injury prone, and summer signing Fred still has to adapt to the rigours of English football. Rabiot could be Mourinho's perfect long term replacement for Matic. The 23 year old can operate as a deep lying playmaker, and start attacks from the back.
Should Pogba leave for Barcelona in the winter or next summer, United will need a world class replacement, and Rabiot on a free would be a bargain.