At the cricket ground, he isn't troubled by ducks (6)
I believe the answer is:
'he isn't troubled by ducks' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'at the cricket ground' is the wordplay.
I cannot quite see how this works, but
'ground' could be 'score' (score is a kind of ground) and 'score' is found within the answer.
A single letter 'r' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for scorer that I've seen before include "Cricket official" , "Film music arranger" , "One keeping count of points earned" , "Sir, not one without heart as a" , "He scratches" .)