Finally Manchester United’s back in American city (4)
I believe the answer is:
reno
'american city' is the definition.
(I've seen this before)
'finally manchester united's back' is the wordplay.
'finally' suggests the final letters.
'united's' says to put letters next to each other.
'back' becomes 'eno' (I am not sure about this - if you are sure you should believe this answer much more).
The final letter of 'manchester' is 'r'.
'r'+'eno'='RENO'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for reno that I've seen before include "Nevada gambling resort" , "American city" , "Nevada marriage and divorce centre" , "US divorce centre" , "Nevada city of Nero" .)