Small individual upset player on pitch (7)
I believe the answer is:
sweeper
'pitch' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'small individual upset player' is the wordplay.
I cannot really understand how this works, but
'small' could be 'wee' (Scottish term for small) and 'wee' is found within the answer.
'player' could be 'e' (I've seen this in other clues) and 'e' is found in the answer.
This explanation may well be incorrect...
'on' is the link.
Can you help me to learn more?
(Other definitions for sweeper that I've seen before include "Last football defender before the goalkeeper" , "cleaner" , "Soccer player" , "Back" , "Soccer defender" .)