Fellow always next to playing field in extreme excitement (5,5)
I believe the answer is:
fever pitch
'extreme excitement' is the definition.
'fever pitch' can be an answer for 'excitement' (I have seen 'Tremendous excitement' mean 'fever pitch' so perhaps 'excitement' could also mean 'fever pitch'). I am not sure about the 'extreme' bit.
'fellow always next to playing field' is the wordplay.
'fellow' becomes 'f' (abbreviation - of a society etc.).
'always' becomes 'ever' (synonyms).
'next to' is a charade indicator (letters next to each other).
'playing field' becomes 'pitch' (eg a football pitch).
'f'+'ever'+'pitch'='FEVER PITCH'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for fever pitch that I've seen before include "in state of great agitation" , "Tremendous excitement" , "State of extreme excitement" , "Height of excitement" , "State of intense excitement - fetch viper (anag)" .)