Assistant putting together team break (8)
I believe the answer is:
sidekick
'assistant' is the definition.
(I have seen 'personal assistant' mean 'sidekick' so perhaps 'assistant' could also mean 'sidekick')
'putting together team break' is the wordplay.
'putting together' says to put letters next to each other.
'team' becomes 'side' (both can mean a sports team).
'break' becomes 'kick' (I can't justify this - if you can you should believe this answer much more).
'side'+'kick' is 'SIDEKICK'.
Can you help me to learn more?
(Other definitions for sidekick that I've seen before include "personal assistant" , "Close friend" , "Junior associate" , "Assistant to a more dominant person (informal)" , "Fellow adventurer - partner or deputy" .)