Defender has to finish (3)
I believe the answer is:
end
'finish' is the definition.
(I know that finish can be written as end)
'defender has' is the wordplay.
'has' says the answer is hidden in the clue.
'END' is hidden within 'defender'.
'to' is the link.
(Other definitions for end that I've seen before include "Purpose of finish" , "Complete" , "Aim; terminate" , "Aim or goal" , "Aim - point - finish" .)