In a sense football team's uneasy (7)
I believe the answer is:
anxious
'uneasy' is the definition.
(I know that uneasy can be written as anxious)
'in a sense football team's' is the wordplay.
'in' means one lot of letters goes inside another.
'sense football' becomes 'nous' (I am not sure about this - if you are sure you should believe this answer much more).
'team' becomes 'XI' (a football team, from Roman numerals for nn).
'a'+'nous'='anous'
'anous' going around 'xi' is 'ANXIOUS'.
Can you help me to learn more?
(Other definitions for anxious that I've seen before include "Apprehensive, uneasy" , "Restless" , "Nervy" , "Fretful, worried" , "On edge" .)