Disadvantage defender after indecisive match (8)
I believe the answer is:
drawback
'disadvantage' is the definition.
(drawback is a kind of disadvantage)
'defender after indecisive match' is the wordplay.
'defender' becomes 'back' (left-backs and right-backs are football defenders).
'after' says to put letters next to each other.
'indecisive match' becomes 'draw' (I can't explain this - if you can you should believe this answer much more).
'back' after 'draw' is 'DRAWBACK'.
Can you help me to learn more?
(Other definitions for drawback that I've seen before include "Disadvantage, problem" , "Fly in the ointment" , "Catch" , "Limitation, disadvantage" , "Hindrance - disadvantage" .)