Minor player's contribution to the score? (5)
I believe the answer is:
extra
'minor player's' is the definition.
'extra' can be an answer for 'player's' (extra is a kind of player). I am not sure about the 'minor' bit.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for extra that I've seen before include "he plays his part" , "person in shot?" , "Actor in crowd scene, no lines" , "Surcharge" , "No-ball or wide, perhaps?" .)