Agent deserted by fine player (5)
I believe the answer is:
'player' is the definition.
'agent deserted by fine' is the wordplay.
'agent' becomes 'factor' (business term for a representative).
'deserted by' is a deletion indicator.
'fine' becomes 'f' (abbreviation).
'factor' with 'f' removed is 'ACTOR'.
(Other definitions for actor that I've seen before include "Croat (anag.)" , "Theatrical player" , "Film star" , "One in a play" , "Films/stage worker" .)