City supporters suffer returning after international (8)
I believe the answer is:
brasilia
'city' is the definition.
(capital of Brazil)
'supporters suffer returning after international' is the wordplay.
'supporters' becomes 'bras' (a bra gives support to breasts).
'suffer' becomes 'ail' (ailing is a kind of suffering).
'returning' is a reversal indicator.
'after' says to put letters next to each other.
'international' becomes 'i' (abbreviation eg in IMF).
'ail' written backwards gives 'lia'.
'lia' put after 'i' is 'ilia'.
'bras'+'ilia'='BRASILIA'
(Other definitions for brasilia that I've seen before include "South American capital" , "SA capital" , "11 [CAPITAL]" , "Capital city of Brazil" .)